The correct answer is: D. No correction required.
The sentence “The good fortune of being your student in my younger days has helped me greatly in my life” is grammatically correct. The phrase “of my being your student” is a prepositional phrase that modifies the noun “fortune.” The preposition “of” is used to indicate possession or association. In this case, the phrase “of my being your student” indicates
that the speaker was fortunate to have been the student of the person being addressed.The other options are incorrect because they do not make sense in the context of the sentence. Option A, “of my having been your student,” is a past participial phrase that modifies the noun “fortune.” However, the sentence does not need a past participial phrase to be grammatically correct. Option B, “of myself being your student,” is a reflexive pronoun phrase that modifies the noun
“fortune.” However, the sentence does not need a reflexive pronoun phrase to be grammatically correct. Option C, “of my being student,” is a noun phrase that modifies the noun “fortune.” However, the noun phrase “of my being student” does not make sense in the context of the sentence.Therefore, the correct answer is: D. No correction required.