What does to 'chip in' mean?

What does the phrase ‘chip in’ means?

Ex.) “Hey, you need to start CHIPPIN’ IN, if you’re livin’ here.” (From the movie ‘8 Mile’)

Also which of the 2 sentences is correct?

a.) What does this phrase mean?
b.) What does this phrase means?
c.) None of the above. (Please give me your revision.)

It means that the person has to make a (financial) contribution to the joint budget.

What does this phrase mean is the correct question. This is question in the present simple . The help verb does is followed by the subject which is followed by the base verb (infinitive).

Look at these examples:

To support mean[color=blue]s to assist. (postive statement in the present simple).
What doe[color=blue]s to support mean?
(question in the present simple).[YSaerTTEW443543]

TOEIC short conversations: Making arrangement for a business meeting[YSaerTTEW443543]

chip in pretty much means help