What is the best way to combine these 2 sentences?

Question

(7)Levi Coffin had been a teacher.
(8) Became a merchant.
A.Levi Coffin had been a teacher, and he was a merchant.
B.Levi Coffin had been a teacher, and then he became a merchant.
C.Levi Coffin had been a teacher and a merchant.
D.Levi Coffin had been a teacher for a merchant.
C?

What change should be made in this sentence?
The Coffins were so good at what they did that Levi Coffin was called the "President of the Underground Railroad."
F.Change Coffins to Coffin's
G.Change good to well
H.Change Railroad to railroad
J.Make no change
Is it F or J? I think it's F

Answer 1

I disagree with your first answer.

Your second answer is J.

Answer 2

Is the first one B?

Answer 3

Yes. B. is the answer for the first one.