Answer:
A. Many cultures were combined together
Step-by-step explanation:
The term "melting pot" is a metaphor that is used to depict that a once heterogenous(more than one) society becomes more homogenous (one) with a common culture between them.
Therefore, the term "melting pot" used in this context means A. Many cultures were combined together because according to the passage, "New York City had many different countries and cultures settled in it"