Answer:
A. adjective clause
Explanation:
The function of the clause is to describe the person; thus, the clause functions as an adjective. An adjective describes a noun or a pronoun.
A. is the correct answer; "Several dirty footprints" makes sense. All the other verbs do not agree with their subjects.
Your scheme is going to be
A
A
B
A
I hope I was able to help. Best of luck!