Which of these is not an example of a compound sentence?
a.
Artichokes used to be considered exotic, but now they appear fairly frequently on menus.
c.
She took the most beautiful photographs of Yosemite Park that I have ever seen.
b.
The Green family takes the recycling process very seriously; they have a bin for everything.
d.
The mosquito problem was horrible this year, but I did not hear of any cases of West Nile virus.
Please select the best answer from the choices provided
A
B
C
D