Which structural element in Sonnet 116 is present in the following two lines: "if this be error and upon me proved, I never writ, nor no man ever loved."
B. quatrain 2
C. quatrain 3
A Shakespearean sonnet has a specific form. It contains three quatrains (4 line stanzas) and a rhyming couplet, and a rhyme scheme of ABAB/CDCD/EFEF/GG. In the case of the example you have posted, Sonnet 116, the first stanza, or quatrain, introduces the author’s point, is that if love is easily shaken, then it is not true love. The second stanza, or quatrain, describes for the reader what true love is. The author talks about it being “an ever fixed mark” (line 5) and “the star to every wandering bark” (line 7); these images imply something steady. The third stanza, or quatrain, talks about the effects of time on love: “Love’s not Time’s fool (line 9). The stanza ends with a rhyming couplet that basically tells the reader that if what the poet has said is not true, then he never wrote poetry. “I never writ, nor no man ever loved.” Therefore, the answer to your question is that those lines are a rhyming couplet, an essential element of Shakespearean sonnets.