Answer: a.

Explanation:
As a rule, women is a noun and female is an adjective. The alternate use, although not strictly wrong, is not universally supported.

Grammar Girl Mignon Fogarty wrote about Woman versus Female. Here’s a snippet:

Testing the validity of the sentence by seeing how it sounds to substitute the word man for woman seems like a good way to see if the sentence makes sense. To me it sounds terribly awkward to say someone is the first man nominee. I imagine most of you would say He’s the first male nominee, if the need arose. So, even though some sources say it’s grammatically correct to use woman as an adjective, my opinion is that you should say Sarah Palin is the first female Republican vice presidential nominee.

With a perfectly acceptable adjective like female available, I don’t see any reason to push woman into the role.

Read the rest of the post

But before you go, can I just say… whether she’s a female or a woman, I hope that Sarah Palin business is over.

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