Read this paragraph about an argument between friends.

sarah and veronica have been friends for years, and like all long–time friends, they often argue. this time it was over who saw the fuchsia–colored shirt first in the window of their favorite store at the mall. both girls wanted to purchase one, but they agreed it was silly to buy the exact same shirts. later that night, veronica realized the argument was juvenile and called sarah to discuss the issue. sarah did not answer the phone. sarah decided not to call her back.

which of the following revisions to the last sentence conveys sarah's feelings using a dependent clause?
a
sarah was still angry at veronica, she decided not to call her back.

b
because sarah was still annoyed at veronica, she decided not to call her back.

c
sarah, very upset, decided not to call her back.

d
in a bad mood, sarah decided not to call her back.