**Core Concept**
The Mini-Mental State Examination (MMSE) is a widely used, 11-question test for cognitive impairment and to screen for dementia. It assesses several cognitive functions, including arithmetic, memory, and orientation. The MMSE is a crucial tool in clinical practice for assessing cognitive status.

**Why the Correct Answer is Right**
The MMSE consists of 11 items, each scored from 0 to 2, except for the orientation to time and place, which is scored from 0 to 1. The maximum possible score is the sum of the maximum points for each item. The correct answer reflects the total number of points that can be achieved in the MMSE.

**Why Each Wrong Option is Incorrect**
**Option A:** 10
This option is incorrect because the MMSE consists of 11 items, not 10.

**Option B:** 20
This option is incorrect because, although some items are scored from 0 to 2, the total maximum score is less than 20.

**Option D:** 30
This option is incorrect because the MMSE has a maximum score lower than 30.

**Clinical Pearl / High-Yield Fact**
The MMSE is a useful screening tool for cognitive impairment, but it is not a definitive diagnostic tool. A score below a certain threshold (usually 24/30) suggests cognitive impairment, but a score above this threshold does not rule out dementia.

**Correct Answer: C. 30**