The correct option is B it also has
An antecedent is a word for which a pronoun stands (ante = "before"). The pronoun must agree with its antecedent in number. Rule: A singular pronoun must replace a singular noun; a plural pronoun must replace a plural noun. Here, the antecedent is 'London' which is a singular noun. Hence, we need a singular pronoun, 'It'. 'One' is also a singular pronoun but it refers to people, not places.