Explanation
The plugging technique can be quite helpful in this particular question. But do not use this technique in every Sentence Equivalence Question you see. That can be counter-productive. Now from the sentence it is clear that the Poetaster initially thought that "Time is needed to write a novel".. i.e time is a necessary and sufficient condition for writing a novel. But as he tried to progress he faced a lot of obstacles and finally gave up. Now lets judge the options-
a) Unworthy
b)idealistic
c)illusory
d)notable
e)ill-fated
f)quixoticUnworthy can be a fit but the lack of similar word in the options cancels it out. Same goes for illusory and ill-fated(which fills up the blank perfectly). Notable doesn't make much sense in the given context.
Only
(B) idealistic and (F) quixotic are synonymous words though and fits in perfectly.