Question

the \landing cards\ that angelina and her family are given mean they
a cannot leave this island.
b are too sick to enter america.
c can enter america.
d must go back to their home country.

Explanation:

Without context about "landing cards", we assume these are immigration - related documents. If they are given landing cards, it usually means they are cleared to enter the destination country. Here the destination is America.

Answer:

C. can enter America