If M and C both have Personal Auto policies with liability limits of 20/30/10, which policy provides coverage if M borrows C's car and injures a pedestrian?

In this scenario, when M borrows C's car and causes injury to a pedestrian, C's Personal Auto Policy will provide coverage for the incident. This is primarily due to the concept of "permissive use" typically included in personal auto insurance policies.

When C gives M permission to use the vehicle, M becomes an insured driver during that period, meaning C's policy extends coverage to M for accidents that occur while driving C's car. C's liability limits apply to any damages that M causes to third parties, such as the injured pedestrian in this case.

M's policy would not provide coverage in this situation because the liability coverage generally applies when the policyholder is driving their own vehicle. In this case, since M was not driving their own car but rather C's, the coverage from M's own policy does not come into play.

Hence, the correct option is that C's policy provides the necessary coverage for the incident involving M and the pedestrian.