Which sentence contains an essential adjective clause?

a. what confuses me is the difference between ultimate and indoor frisbee rules.

b. because of weather conditions, some countries only play indoor ultimate frisbee.

c. indoor ultimate frisbee is the only version that i enjoy playing.

d. indoor ultimate frisbee, which is another version of the sport, requires fewer players.

Excerpted from "the children's hour" by henry wadsworth longfellow a whisper, and then a silence: yet i know by their merry eyes they are plotting and planning together to take me by surprise. a sudden rush from the stairway, a sudden raid from the hall! by three doors left unguarded they enter my castle wall! look carefully at the lines above. a poem with this particular rhyme scheme is best read a. line by line. b. with long pauses. c. phrase by phrase. d. with a strong rhythm.