What does the Intelligence Quotient (IQ) represent?

The Intelligence Quotient (IQ) is primarily understood as a measure of an individual's reasoning ability, which is quantified and compared to a standard norm established by a large population. This statistical score helps in assessing cognitive capabilities such as problem-solving, logical reasoning, and abstract thinking. It is designed to provide insight into an individual's intellectual potential, showing how their cognitive skills measure up against the population average. Hence, option B correctly captures the essence of what IQ represents, as it emphasizes the reasoning ability aspect of intelligence in a comparative framework.

Other options address different facets of human capability but do not accurately describe what IQ measures. Leadership abilities or emotional intelligence, for instance, encompass skills that go beyond mere cognitive reasoning and involve a range of social and personal competencies that are not captured by traditional IQ tests. Similarly, while practical problem solving is an important skill, IQ scores specifically focus on reasoning and cognitive abilities rather than practical situations or emotional contexts.