A. Even before the CEO's announcement, 75% of the employees worked from 9:00 to 18:00.
No Impact, this option doesn't show how lack of flexibility will have an adverse effect on employees' productivity.
B. When all employees work the same hours, scheduling meetings is easier.
Weakens, this option shows that lack of flexibility will led to more productivity.
C. 65% of the company's employees are women.
No Impact, so what? We can't assume women will be vulnerable to lack of flexibility. No such info is given in the passage.
D. Company X's employees consistently point the ability to start working at the hour they choose as the number one advantage of working for Company X.
Strengthens, this option hints that employees are happy today because of flexibility, if that is taken away then it can affect their mental stability and can lead to deterioration of productivitiy.
E. The CEO is a high-ranking former military.
No Impact, so what? This option doesn't show how lack of flexibility will have an adverse effect on employees' productivity.