Answer: A) The French girl who wears the yellow leather coat was here about an hour ago.
Step-by-step explanation: The subject of a sentence is the person or thing that performs the action of the verb. From the given options, the sentences that contains a clause used to modify the subject, is the corresponding to option A: "The French girl who wears the yellow leather coat was here about an hour ago", the subject of that sentence is "The French girl" and the clause that modifies it is "who wears the yellow leather coat."