The correct answer is B. it does not follow a formal structure.
Let us first go through all of these options in order to determine the structural characteristics of <em>Forgetfulness, </em>by Billy Collins.
Option A is incorrect - if you count the syllables in each line, you will see that the first one has 11, the second one 13, and so on - so, not 10.
Option C is also incorrect - there are actually 8 stanzas, and they are not of equal length.
Option D is also incorrect - there are no rhymes in this poem.
So, by the process of elimination, the correct answer is B - this poem doesn't follow a formal structure - it is rather a free verse poem containing stanzas of varying lengths.
The main idea of this poem is welcoming the new year and spring as an opportunity for a fresh start and new love. The closing lines sum up the main idea well:
"Then you faire flowre, in whome fresh youth doth raine,
<span> prepare your selfe new love to entertaine."
The 'fair flower' he is referring to is a woman, and he is telling her to get ready ('prepare your selfe') to entertain (discover) new love!</span>
