## Core Concept
The question tests knowledge of the biochemical characteristics of *Neisseria meningitidis*, commonly referred to as meningococci. This bacterium is a significant cause of bacterial meningitis and sepsis. Its identification in the laboratory often relies on its biochemical properties.

## Why the Correct Answer is Right
Meningococci are known for their specific biochemical reactions which help in their identification. They are **oxidase-positive**, which is a critical test for their preliminary identification. They also **ferment glucose and maltose** but not **sucrose** or **lactose**. The correct answer, which is not found in meningococci, relates to their inability to ferment certain sugars.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because meningococci do have certain specific characteristics that can be identified through biochemical tests.
- **Option B:** This is incorrect because it likely represents a characteristic that meningococci do possess, such as the ability to ferment glucose.
- **Option C:** This option might seem plausible but given that meningococci can ferment glucose and maltose, this option could be related to a characteristic they possess.
- **Option D:** Given that **D. lactose** is the correct answer, explaining why the other options are incorrect helps understand that meningococci are known to ferment glucose and maltose but not lactose.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that meningococci can cause severe disease rapidly. Early identification and treatment are crucial. Laboratory identification often involves noting their **Gram-negative diplococci** appearance and specific biochemical reactions.

## Correct Answer: D. lactose