Question

the vietcong were rebels in south vietnam who wanted to
rid both north and south vietnam of communist influence.
spread the catholic religion throughout vietnam
overthrow the communists who controlled the country.
unify the south and north under a communist government.

Explanation:

The Vietcong were communist-aligned rebels in South Vietnam whose core goal was to unify North and South Vietnam under a communist government, aligning with North Vietnam's communist leadership. The other options are incorrect: they did not oppose communist influence, their aim was not religious spread, and they sought to install communist control, not overthrow it.

Answer:

unify the South and North under a Communist government.