Explanation
Creating a filter: in this question, when we read the
prompt, we pause at "had been." We're always suspicious of the past perfect,
because it's overused. For it to be warranted, the action had to happen before
something else. But before what, in this case? Not the "carrying on." He was no
more successful, ultimately -- that is, after he had carried on
the tradition, not before. Gottlob Frege, similarly, came before the ultimate
lack of success, not after. Drawing a timeline with the events on it can
clarify this; the past perfect tense has to come to the left of an event in the
simple past tense.
Applying the filter: So, fixing the tense, the answer is
(B). Choice (E) has the same tense problem as the original sentence. Choices
(C) and (D) both distort the intended meaning by messing around with the
expression of goals and methods. The correct answer is (B).
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