When thinking about this kind of question you should stop to think about what the Tea Act was actually trying to accomplish. When the Tea Act was passed, the British East India Company was struggling on the edge of bankruptcy. At the same time, the Company was facing a severe surplus in excess tea. The purpose of the Tea Act represented an attempt to save the East India Company.

In the process, the Tea Act would have had the effect of actually lowering the cost of tea in the colonies (and this is a feature that should not be ignored). Be aware: your question is focused on the British perspective and on Britain's intentions. Keep this in mind when you answer it.

Of the options given here, B is the best answer. 

Lord North was definitely trying to save the East India Company.  The company was losing money because Americans were refusing to buy tea from England.  Lord North was hoping that the new Tea Act would induce the Americans to buy tea again.  This would save the company.

The Tea Act was also designed to make the colonists happy.  After all, they would have to like the new law if they were to start buying tea again.  North felt that the low prices on the tea would please the colonists.

For these reasons, B is the best answer.