Directions: In the sentence given below, one/some parts have errors and others are correct. Find out which part has an error and mark it as your answer. If there is no error, mark 'No error' as your answer.

The US Immigration and Customs Enforcement has decided that international students/ (A) whose courses have completely gone online will have to return/ (B) to their home countries. At the same time, the directive reiterates that/ (C) international students cannot take more than one class or three credits online./ (D)