The correct answer is: c) Both a and b.
Andhra Pradesh receives rainfall primarily from the southwest monsoon and the northeast monsoon. The southwest monsoon is the dominant monsoon in Andhra Pradesh, bringing most of the state’s rainfall. The northeast monsoon brings less rainfall than the southwest monsoon, but it is still an important source of rainfall for the state.
The southwest monsoon is a seasonal wind that blows from the southwest to the northeast across the Indian subcontinent. It is caused by the difference in temperature between the land and the ocean. The land heats up faster than the ocean, causing the air to rise over the land. This creates an area of low pressure over the land. The air from the ocean, which is cooler and at higher pressure, flows in to fill this low pressure area. This flow of air is the southwest monsoon.
The southwest monsoon arrives in Andhra Pradesh in June and stays until September. The heaviest rainfall occurs in July and August. The southwest monsoon brings an average of 700-800 mm of rainfall to Andhra Pradesh.
The northeast monsoon is a seasonal wind that blows from the northeast to the southwest across the Indian subcontinent. It is caused by the difference in temperature between the land and the ocean. The land cools down faster than the ocean, causing the air to sink over the land. This creates an area of high pressure over the land. The air from the ocean, which is warmer and at lower pressure, flows in to fill this high pressure area. This flow of air is the northeast monsoon.
The northeast monsoon arrives in Andhra Pradesh in October and stays until December. The heaviest rainfall occurs in November and December. The northeast monsoon brings an average of 200-300 mm of rainfall to Andhra Pradesh.
In addition to the southwest and northeast monsoons, Andhra Pradesh also receives some rainfall from western disturbances. Western disturbances are low-pressure systems that form over the Mediterranean Sea and move eastward across the Indian subcontinent. They bring occasional showers and thunderstorms to Andhra Pradesh.