The correct answer is D. fallacies. Logical fallacies are faults in somebody's logic - inaccuracies, wrong deductions and information, false details and conclusions, etc. A and B are definitely incorrect even if you don't know what they are - these are adjectives and don't fit into this sentence because we need a noun. C is also incorrect because that noun has to be plural in this context.
Most number of questions that are asked not only to the poems writer but also to the writer of other literature themselves are their inspiration that would have caused them to write the literature. Also, this represent how interest the readers are regarding the literature.