In this context, make it to means "arrive at a certain place", and there is often an implied time constraint.
For example, my son might say:
I missed the bus. Now I won't make it to school.
This could mean that there's no way he can get to school, or it could mean there is no way he can get to school without being late.
In your example, we can assume that cars can't drive to the airport now, because the avalanche has covered the road and made it impassible. The road still goes to the airport, so answer (b) is incorrect. However, the people traveling to the airport may not be able to get to the airport – not until the road is cleared off and reopened. If Lucy and Luis have tickets for a flight that leaves in two hours, and the road won't be reopened for several hours, there's a good chance they won't make it to the airport, and there's a good chance they won't make their flight, either.