It _____________ not look like a great deal today, but back then it was a coup: no man before ___________ to import tea directly into Ireland. The option that will best fill the blanks in the
above sentences would be:

From the narrative, it is clear that the act of importing tea into Ireland is an event of the past and that perhaps doing so today is not a "big deal". This means that the act of importing tea should be spoken of in the past perfect tense as we are referring to a past event (of importing tea directly) when standing at a point which itself is a point of past from today's perspective (the point when it was considered a coup). Hence, "had dared" is the most apt for the second blank and hence, B should be the answer.

The sequence of events has to be understood like this: daring to import tea ---> being considered as a coup ----> not a big deal today.