Question

Which words in the sentence are the adverb clause?
Wherever Rover roams, he always comes home afterward to sit by the back door.
a. by the back door
b. he always comes home
c. afterward to sit by the back door
d. wherever Rover roams

Answer 1

The answer is c. afterward to sit by the back door
An adverb clause is a word of words that modify a verb, adjective, or adverb

Answer 2

The correct answer is D, because that is the only subordinate/adverb clause among these examples. A is an adverbial phrase, not a clause - it doesn't have an active verb. B is a complete independent sentence. C cannot be a clause, because it doesn't have an active verb - 'to sit' is an infinitive, it isn't active or passive.