The antecedent of the underlined personal pronoun is B. FEW.
Few is an indefinite pronoun that serves as an antecedent. It is also in plural form. Therefore, the referent, THEIR, is also in plural form.
Pronoun is a word used to take the place of a noun. It must agree to the number of the antecedent.
If the antecedent is singular, then the pronoun should be singular.
If the antecedent is plural, then the pronoun should be plural.