Which of the following is a compound-complex sentence?
a.
Because Cheryl is a farmer, she has very strong opinions about GMOs.
b.
Cheryl, a farmer, has very strong opinions about GMOs.
c.
Cheryl is a farmer, but she hasn't shared her opinions with me.
d.
Because Cheryl is a farmer, she has very strong opinions about GMOs, but she hasn't shared them with me.