A.I. Explanation:

Option 1: "It acts as the primary barrier against environmental hazards."

Explanation: This option is incorrect because the text does not mention the subcutaneous layer acting as a barrier. The primary barrier function is typically associated with the epidermis, which is the outermost layer of skin.

Option 2: "It provides colour and pigmentation to the skin."

Explanation: This option is incorrect as the text does not attribute color or pigmentation to the subcutaneous layer. Instead, pigmentation is primarily a function of the epidermis, where melanin is produced.

Option 3: "It supplies nutrients to the other layers and insulates the body."

Explanation: This option is correct because the text explicitly states that the subcutaneous layer of fat supplies nutrients to the other layers and cushions and insulates the body. This aligns perfectly with the main idea presented in the text.

Option 4: "It is responsible for the sensation of touch and pain."

Explanation: This option is incorrect because the sensation of touch and pain is primarily associated with the dermis, which contains nerve endings. The text does not attribute this function to the subcutaneous layer.