The basic unit of meter in poetry is a foot.
Syllable would be the correct answer if the option said 'stressed or unstressed syllable,' because there are two types of syllables, not only the unstressed one. An iamb and a trochee are types of feet in poetry, so they are incorrect as well. A foot is a unit of meter which consists of a number of syllables.
There isn't a passage or answers to select from so you probably will not get an answer without being specific.
However. I think yes hope it helps
The right answer is: B. RE: Stop By My Office Later
