Please make sure to bring the following items a valid ID, your student transcript, and proof of residency.
Correct: B
A colon is used to introduce a list or explanation, especially when the preceding clause is a complete thought (an independent clause). 'Please make sure to bring the following items' is an independent clause. The list that follows is introduced by 'the following items'. Therefore, a colon is the correct punctuation mark. Option B correctly uses a colon.