It is not until a Vietnamese girl getting 18 years old that she is allowed to get married legally.
A. A Vietnamese girl is not allowed to get married legally only when she gets 18 years old.
B. A Vietnamese girl is allowed to get married legally only after she gets 18 years old.
C. They never allow a Vietnamese girl to get married legally when she is 18 years old.
D. The legal allowance for a Vietnamese girl to get married will be issued in 18 years.