Hi!
Answer: B. An iamb consists of an unstressed syllable followed by a stressed syllable
So iambs constitute a group of stressed and un streesed syllables and sonnets are written in iambic pentameters. An iambic parameter usually uses 10 syllables, 5 stressed and 5 unstressed ones.
In sonnet 29 where Shakespere talks about how love has the power to overcome and turn around the feelings of despair and depression, we can conclude that its iambs consists of an unstressed syllable followed by a stressed syllable. Therefore, the answer is B.