Answer:
B. It answers the question when and modifies the verb put.
Step-by-step explanation:
The given sentence - When you get home from the game, put your dirty clothes in the hamper - a complex sentence.
A complex sentence contains an independent clause and at least one dependent clause. An independent clause can stand alone as a sentence as it has a complete thought, we can understand what is going on and we get the full information on a subject. A dependent clause cannot stand alone as it doesn't have a complete thought, even though it can have a subject and a verb.
In our case:
The independent clause - put your dirty clothes in the hamper.
The dependent clause - When you get home from the game.
Our dependent clause is adverbial. These are some of the common purposes of adverbial causes and common subordinating conjunctions:
Condition: if, unless
Reason: because, since, as
Time: before, after, while, as soon as, when, since, until
Purpose: in order to, so that
Concession: although, though, even though, while, whereas
So we see our dependent clause is an adverbial clause of time as it has a conjunction of time, and is attached to the main clause with the subordinating conjunction 'when'. It explains the verb put, it shows exactly in what time the doer should put the clothes in the hamper.
I hope it helped you :)