Answer:
show or explain to (someone) how to do something.
Explanation:
the third one, if you add the comma without the when then you would have a comma splice (when you put a comma between 2 independent clauses without a conjunction) adding the when before Cynthia makes the first part a dependent variable and makes it okay to add the comma!
Hope this helps! :)
Answer:
The answer is D.) My mistress is not a perfect beauty.