**Core Concept**
The Intelligence Quotient (IQ) is a standardized score that measures human intelligence, specifically cognitive abilities such as reasoning, problem-solving, and thinking. It is calculated based on a person's mental age, which is their age-adjusted score on a standardized test, and their chronological age.

**Why the Correct Answer is Right**
IQ is a widely used metric to assess cognitive abilities in children and adults. The score is calculated by dividing the mental age by the chronological age, then multiplying by 100. For example, a child with a mental age of 12 and a chronological age of 10 would have an IQ of 120 (12/10 x 100). This score indicates that the child's cognitive abilities are 20% above the average for their age group. The Stanford-Binet Intelligence Scale and the Wechsler Intelligence Scale for Children (WISC) are two commonly used IQ tests.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because IQ does not measure emotional intelligence, social skills, or creativity, although these factors can influence an individual's overall cognitive abilities.
**Option B:** This option is incorrect because IQ is not a measure of academic achievement, although a high IQ score may indicate a higher likelihood of academic success.
**Option C:** This option is incorrect because IQ is not a measure of physical ability or athleticism.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that IQ scores are not absolute measures of intelligence, and they should be interpreted in the context of the individual's cultural, social, and educational background.

**Correct Answer: C. IQ is a standardized score that measures human intelligence, specifically cognitive abilities such as reasoning, problem-solving, and thinking.**