oh please, google did their own study. They want to hire more females than any company but the conclusion was that there aren't enough women in the engineering pipeline.
So yea, the more likely reason is
C) Women don't want to become engineers as much as men do, for whatever (social/biological/cultural) reason
So yea, the more likely reason is C) Women don't want to become engineers as much as men do, for whatever (social/biological/cultural) reason