Which sentence is correctly punctuated?
a. during the parade, we walked with: the bakers, the jeffersons, and the wrights.
b. today, people can watch television on: a laptop, a tablet, or a cell phone.
c. sarah went to the theater with carlotta, tina, and roxanne.
d. hank grilled hamburgers and hot dogs for: his cousin, his brother, and his uncles.