Answer:
C. whose shoes were tied together.
Step-by-step explanation:
Relative clauses are those clauses that begin with a relative pronoun and contains a verb and a subject. They are also dependent clauses and cannot stand as a sentence on their own.
In the given sentence, the relative clause is "whose shoes were tied together". This is because it starts with a relative pronoun "whose", and also acts as an adjective and is a dependent clause.
Thus, the correct answer is option C.