Receptors as drug targets are actually:

The correct answer is Option (4) → Proteins

Drugs act by interacting with biological macromolecules called drug targets, mainly enzymes and receptors. Receptors are proteins that take part in communication within the body. Most of them are embedded in cell membranes with their active site facing outwards, so that chemical messengers (such as neurotransmitters and hormones) can bind to them and pass the message into the cell.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.