I have seen two versions of the same question:

1. A study on couples' retirement transitions found that women who took new jobs after retiring from their primary careers reported high marital satisfaction, more than when retiring completely.

(A) more than when retiring
(B) more than if they were to retire
(C) more so than those who retired
(D) which was more so than those retiring
(E) which was more than if they had retired

OA is C

2. A study on couples' retirement transitions found that women who took new jobs after retiring from their primary careers reported high marital satisfaction, more so than those who retired completely.
A. more so than those who retired
B. which was more than if they had retired
C. more than when retiring
D. more than if they were to retire
E. which was more so than those retiring

OA is A . Both the answers are also in sync. And no issue in understanding the same. However, in question 1 while reading we are not clear of meaning, in that case we are not sure whether the author meant meaning B or C . Question 1 might be misinterpreted by someone who compiled the document , but I expert help please. If Q1 is correct as given, then nothing stops us to go for answer choice B as question does not give clear direction for meaning.