The correct answer is C: Iambic Pentameter
Iambic Pentameter is a type of metric line used in traditional English poetry and verse drama. "Pentameter" indicates a line of five "feet".
The foot has an unstressed syllable followed by a stressed syllable. This pattern repeats five times in each line, as we can see below:
U: unstressed
S: stressed
U---S----U---S----U----S------U----S-----U------S
I'm go | ing out | to clean | the pas | ture spring;
U---S---U---S-----U----S----U----S---------U---S
I'll on | ly stop | to rake | the leaves | away
U---------S----U---S--------U----S---U----S------U---S
(And wait | to watch | the wa | ter clear, | I may):
U------S----U---S-------U----------S-----S---S--S
I sha'n't | be gone | long.—You | come too.
U---S-----U-----S---U----S-----U----S---U---S
I'm go | ing out | to fetch | the lit | tle calf
U---------S------U----S-----U----S----U----S------U---S
That's stan | ding by | the mo | ther. It's | so young,
U--S----U------S------U----S-------U--S-----U-----S
It tot | ters when | she licks | it with | her tongue.
U------S----U---S-------U----------S-----S---S--S
I sha'n't | be gone | long.—You | come too.