Which of these is not a compound sentence?
a.
Jacob is a very sweet child most of the time, but he occasionally has temper tantrums.
c.
Curtis did not know that he wrote a bad check.
b.
She knew how to use most of the programs, but she was unfamiliar with Photoshop.
d.
none of these
Please select the best answer from the choices provided
A
B
C
D