Which answer choice is a sentence fragment?
a) almost before the casserole had begun to cool on top of mrs. ruben's new black granite kitchen countertop.

b) each morning as the sun rose above the hills, matthew walked diligently to the golf course to begin his day.

c) every afternoon, grandma ayla would come out on her back porch, shuffle down to the shore, and feed the ducks.

d) julie noticed that almost all of the billboards on the roadside for the past 50 miles had been political ads.