The process of admitting a new State begins with
A. an invitation from Congress.
B. congressional review of the potential
State's constitution.
C. the area's residents asking Congress
for admission.
D. a vote in neighboring States.

I think C. the area's residents asking Congress for admission.

Explanation:

Typically, a territory sends representatives and two senators to push for statehood. Congress has the power to admit a new state, but the president has to sign the territory into statehood to make it official.

c holding free elections