The line from John Keats' poem that is written in iambic pentameter is C. Fade far away, dissolve, and quite forget.
Pentameter means that there are 5 meters in a line; one meter consists of 2 syllables, which means that a pentameter has 5 * 2 = 10 syllables in one line. The only option here that has 10 syllables is C. A has 6, B has 6, and D has 11.
I'd say option B, because that is how the story or the main problem was "resolved" (as the phrase suggests) or taken care of.
