**Core Concept**
The question requires the application of the Intelligence Quotient (IQ) formula to determine the cognitive abilities of a child. IQ is a score derived from standardized tests designed to measure human intelligence, with an average score of 100 and a standard deviation of 15. The formula for calculating IQ is: IQ = (MA / CA) x 100, where MA is the Mental Age and CA is the Chronological Age.

**Why the Correct Answer is Right**
In this scenario, the child's chronological age is 15 years, and the mental age is 9 years. Using the IQ formula: IQ = (9 / 15) x 100 = 60. This indicates that the child's cognitive abilities are below average, suggesting a developmental or intellectual disability. The calculation of IQ helps in understanding the child's cognitive abilities and determining the appropriate interventions.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided.
* **Option B:** This option is not provided.
* **Option C:** This option is not provided.
* **Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
A common formula to remember is: IQ = (MA / CA) x 100. This formula is essential in determining the cognitive abilities of children and adults with developmental or intellectual disabilities.

**Correct Answer:**
60