Answer:
C. she does not eat meat but her husband does
Step-by-step explanation:
A- "but" is used to introduce a phrase that contrasts what has already been said. so if it was "she can eat meat" it wouldn't make sense because the next phrase does not contradict that
B- "she did not eat meat" is in past sense but "her husband does" is in simple present tense so it wouldn't make sense
C- "she does not eat meat but her husband does" is in simple present tense and "she does not eat meat" and "her husband does" contrast each other so it is the answer