-Is this your first visit to London? -No, I ___ here several times before and I ___ quite at home in London. ?

The correct answer is B) "have been/feel" because it accurately conveys the speaker's past experiences and current feelings about London.

In the first part of the sentence, "I have been here several times before," the present perfect tense ("have been") is used. This tense is appropriate because it indicates experiences that occurred at an unspecified time in the past and have relevance to the present. The speaker's multiple visits to London contribute to their current familiarity with the city.

In the second part, "I feel quite at home in London," the present simple tense ("feel") is used to express a current, ongoing state of being. This choice effectively communicates that the speaker’s sense of comfort in London is a present reality, arising from their previous experiences.

The other options either misapply tenses or do not align with the context of combining past experiences with present feelings. For example, option A ("was/have felt") implies a completed action and changes the meaning, while C ("had been/felt") suggests that the experiences occurred before a past moment, which is not applicable here. Option D incorrectly uses "has been," indicating a singular subject that does not match the speaker. Thus, B is the most coherent and contextually appropriate choice.