Determine the meter of the following line.

I almost fell asleep.

trochaic

iambic

anapestic

dactylic

The meter of this line is iambic.

Iamb consists of an unstressed syllable followed by a stressed syllable. So here, I is unstressed, al - is stressed, most is unstressed, fell is stressed, a - is unstressed, and sleep is stressed.

Trochee is quite the opposite, so that is incorrect, and anapest and dactyl refer to three syllables.