The correct answer is option 4: I and III only.

Statement I is correct because the south-west monsoon first reaches the Malabar coast in southwestern India, bringing heavy rainfall to that region.

Statement II is incorrect because Rajasthan does receive rainfall from the south-west monsoon. Although it is a desert region, it does experience some rainfall during the monsoon season.

Statement III is correct because the south-west monsoon retreats when the permanent wind belts start shifting to the south. This indicates the end of the monsoon season as the monsoon winds withdraw from the subcontinent.

Therefore, options 1, 2, and 3 are incorrect as they do not include the correct combination of statements.

Alert - correct answer should be option 1: I, II, and III.