• them vs. theirs

[niue]

Hi!
I read the following in a TOEIC book:

“Question 112. Since the company had so many unsold products from last year, they had to sell ____ at a hugely discounted rate.

A. they
B. their
C. theirs
D. them

(Answer: D)” ((Mozilge TOEIC, Book 5, Test 6))

I agree with the above book that D is correct, but I don’t understand why C isn’t.
Don’t you think that C [theirs = their products] IS ALSO correct?
Thanks in advance.

 

[Raymott]

Hi!
I read the following in a TOEIC book:

“Question 112. Since the company had so many unsold products from last year, they had to sell ____ at a hugely discounted rate.

A. they
B. their
C. theirs
D. them

(Answer: D)” ((Mozilge TOEIC, Book 5, Test 6))

I agree with the above book that D is correct, but I don’t understand why C isn’t.
Don’t you think that C [theirs = their products] IS ALSO correct?
Thanks in advance.

No, it's not correct. Consider this: "I've just read your question, and I'd like to answer yours/it." Do you see that 'yours' is not right, even though it does refer to 'your question', and that it should be 'it'.
Another example: Company A had to sell their products, and company B had to sell theirs/them as well." In this case, only 'theirs' works.