Using a verb from the list given below, complete the conversation:
happen / meet / be / seeA: Is Brussels an interesting place?
B: I have no idea. [fill-regular] there.

In the given question, we've to fill the blank with the foremost suitable type of a verb that's given within the question.
In order to try and do this, allow us to take a glance at the given verbs, one by one.
The verb, happen, is employed to visit an occasion while the verb, meet, is employed to confer with get the corporate of somebody. The verb, be, is employed to check with being present somewhere and also the verb, see, is employed to talk to witness something.
In the given question, the context is visiting an area. In such a context of visiting an area, the foremost appropriate verb which will be used would be the verb ‘be’, because it is employed to being present somewhere. Hence, to fill the blank we'd like to use an option that uses this verb.

From the given options we are able to see that the sole option within which the verb ‘be’ is employed is in option ‘D’, I’ve never been. Though this is often a participial sort of ‘be’, it's still the foremost apt choice to be used. Therefore, option ‘D’ is that the correct answer. So, options ‘A’, ‘B’ and ‘C’ are incorrect.

Note: in a very situation where the meaning of the given option isn't clear, use the elimination method and take away the words that you just think are least likely to be right, so as to succeed in the ultimate answer.