The correct answer is: a) Kharif
Kharif is the primary rice-growing season in Assam. It is the rainy season, which runs from June to September. The monsoon rains provide the water that is needed for rice cultivation. The main crops grown during the Kharif season are rice, maize, and jute.
Rabi is the winter season, which runs from October to March. The Rabi season is a good time to grow wheat, barley, and mustard.
Zaid is the summer season, which runs from April to May. The Zaid season is a good time to grow vegetables, fruits, and pulses.
Pre-Kharif is the period of time before the Kharif season. It is a good time to prepare the land for rice cultivation.