**Core Concept**
Neisseria meningitidis and Neisseria gonorrhoeae are two closely related species of Gram-negative diplococci that cause distinct infections. The key to differentiating between these pathogens lies in their biochemical and genetic characteristics.

**Why the Correct Answer is Right**
The correct answer is based on the ability of Neisseria species to ferment certain sugars. Neisseria meningitidis can ferment maltose, whereas Neisseria gonorrhoeae cannot. This property is due to the presence of the maltose-ferrmenting enzyme maltose 4-epimerase in N. meningitidis. This enzyme is encoded by the malE gene, which is present in N. meningitidis but absent in N. gonorrhoeae. This genetic difference allows for the differentiation of these two species based on their ability to ferment maltose.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe a method for differentiating N. meningitidis from N. gonorrhoeae.
**Option B:** This option is incorrect because it is a characteristic shared by both N. meningitidis and N. gonorrhoeae, and therefore does not differentiate between the two species.
**Option C:** This option is incorrect because it is a characteristic that can be present in both N. meningitidis and N. gonorrhoeae, and does not provide a clear distinction between the two species.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the ability to ferment maltose is a key identifying feature of N. meningitidis, and this characteristic can be used to differentiate it from N. gonorrhoeae in the laboratory.

**Correct Answer:** C.