In chapter three of William Golding's Lord of the Flies, Jack's description is developed primarily through which of the following:
Jack Merridew is a character in Lord of the Flies, by William Golding, and by chapter three of the novel it is clear that Jack is obsessed with hunting. The key to your question is the words "primarily developed," and I assume the question refers to the beginning of the chapter, which is dedicated to a description of Jack.
There is little hyperbole in this passage; while Jack's behavior does seem a bit outrageous and exaggerated, the language is not. Metonymy is not applicable, either, as there are no parts representing the whole. Since Jack is already a person, he cannot be personified (given human qualities or characteristics). That leaves metaphor and simile.
The obvious choice might be B, as there is a simile in the second sentence of the description:
Jack was bent double. He was down like a sprinter, his nose only a few inches from the humid earth.
Unfortunately, this simile only describes his physical stance for a moment rather than a complete description of Jack in these paragraphs. Over the course of the three descriptive paragraphs, the more likely answer is A, metaphor. Golding uses specific details over three paragraphs which compare Jack to a hunting dog on the trail of his prey--in this case, a pig.
He is bent over on the trail, his nose nearly on the ground, sniffing the pig tracks.
There was only the faintest indication of a trail here; a cracked twig and what might be the impression of one side of a hoof. He lowered his chin and stared at the traces as though he would force them to speak to him. Then dog-like, uncomfortably on all fours yet unheeding his discomfort, he stole forward ﬁve yards and stopped. Here was loop of creeper with a tendril pendant from a node. The tendril was polished on the underside; pigs, passing through the loop, brushed it with their bristly hide.
Just like a hunting dog (Golding even uses the word "dog-like") seeking his quarry, his nose is near the ground and he is moving forward "on all fours." He sniffs, walks, then stops and sniffs again.
Jack crouched with his face a few inches away from this clue, then stared forward into the semi-darkness of the undergrowth.... A sharpened stick about ﬁve feet long trailed from his right hand, and except for a pair of tattered shorts held up by his knife-belt he was naked. He closed his eyes, raised his head and breathed in gently with ﬂared nostrils, assessing the current of warm air for information. The forest and he were very still.
As he continues his search, Jack stops again and tries to catch the pigs' scent "gently with flared nostrils."
At length he let out his breath in a long sigh and opened his eyes. They were bright blue, eyes that in this frustration seemed bolting and nearly mad. He passed his tongue across dry lips and scanned the uncommunicative forest. Then again he stole forward and cast this way and that over the ground.
This final image is exactly the same thing one might see if a dog were sniffing out a trail. As he searches, he casts his head (and more specifically his nose) "this way and that," hoping to catch the scent he is so desperate to discover.
In this description, Jack is being compared, indirectly, to a hunting dog on the scent of his prey. It is a metaphor.