## Core Concept
The diagnosis of mania, a key feature of bipolar disorder, relies on specific clinical criteria, including the duration of symptoms. Mania is characterized by a distinct period of abnormally elevated, expansive, or irritable mood.

## Why the Correct Answer is Right
The correct answer, , indicates that a minimum duration of 1 week of symptoms is required for the diagnosis of mania, according to the DSM-5 criteria. This duration criterion helps differentiate mania from normal mood fluctuations or brief episodes of elevated mood. During this period, at least three of the following symptoms must be present: inflated self-esteem or grandiosity, decreased need for sleep, more talkative than usual or pressure to keep talking, flight of ideas or racing thoughts, distractibility, increase in goal-directed activity, and excessive involvement in activities that have a high potential for painful consequences.

## Why Each Wrong Option is Incorrect
* **Option A:** is incorrect because 2 days is too short a duration for diagnosing mania; it might represent a brief mood episode that doesn't meet full criteria.
* **Option B:** is incorrect because, although 4 days could seem like a reasonable duration for some mood disorders, it does not meet the full criteria for mania.
* **Option D:** is incorrect because 14 days exceeds the minimum required duration for diagnosing mania and might be more relevant for other conditions.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that if the mood episode includes both manic and depressive symptoms (mixed features), the diagnosis can still be made with a duration of at least 7 days or less if hospitalization is required. Also, note that hypomania, a milder form of mania, requires a duration of at least 4 days.

## Correct Answer: C. 1 week.