Answer:
The correct answer is: A) ;.
Step-by-step explanation:
Semicolons (;) are used to connect independent clauses that are related to one another. This means that it turns two sentences that could be complete on their own into one larger sentence. In this case, the first independent clause states the sudden change in temperature, while the second one talks about how the speaker was glad to had brought a warmer item of clothing to wear in this now colder environment.