Answer:
B). Ms. Jones, whom you have met, is my teacher.
Explanation:
Relative pronouns are demonstrated as the pronouns that are employed either to link a clause or phrase to the noun or to add description about the noun/subject in the sentence. These pronouns acts as a subject that are dependent to specify its meaning.
As per the question, option B displays the sentence that involves a relative pronoun 'whom' that opens/introduces(act as a conjunction) the relative clause 'whom...teacher'(dependent to accomplish its meaning) that functions to modify the noun 'Ms. Jones'. Thus, option B is the correct answer.