## **Core Concept**
The question pertains to the Kuppuswamy scale, which is a tool used to assess the socioeconomic status (SES) of an individual or family in an urban area. The scale takes into account parameters such as education and occupation of the family members and income per month.

## **Why the Correct Answer is Right**
The Kuppuswamy scale categorizes the population into five socioeconomic classes (or grades) based on the education and occupation of the family head and the monthly family income. Skilled workers typically fall into a specific category that reflects their level of education and occupation.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not accurately represent the socioeconomic grade for skilled workers according to the Kuppuswamy scale.
- **Option B:** This option is incorrect as it does not correspond to the correct classification for skilled jobs.
- **Option D:** This option is incorrect because it represents a different socioeconomic category.

## **Clinical Pearl / High-Yield Fact**
Recall that the Kuppuswamy scale is often used in epidemiological studies to stratify populations based on their socioeconomic status, which can be an important factor in health outcomes and access to healthcare.

## **Correct Answer:** . Upper middle class.