Which sentence uses the correct comparative form of the adjective pretty? a. that blue dress is the prettiest one on the rack. b. this blouse is prettier than the one that got stained. c. those flowers are very pretty. d. i think yellow roses are more prettier than red roses.

Usually a comparative adjective takes on the ending -er
Therefore you can eliminate A and C from the list.
You are left with B and D, however in D it says more prettier which is incorrect grammar therefore it must be... 
B

The short story "Sol Painting, Inc.", written by Meg Medina, is about a girl named Merci who wants to continue her father’s legacy and business. Her mother wants her to get into a nice school, so they make a deal. While holding their end of the bargain, snobby girls ruin their work, and Merci wants her dad to stand up for her, but instead, he is quiet and respectful.

theme: It's harder to be yourself when you've made a bad impression.

hope it helps this is all i could think of and find

please mark me brainliest

: )

Explanation: