The correct sequence of foodgrains production (in decreasing order) in India is Rice—Wheat—Coarse cereals—Pulses, as indicated by option 4.

Let`s dissect each option for better understanding:

1. Wheat—Rice—Pulses—Coarse: This option suggests that wheat is the most produced, followed by rice, then pulses and coarse cereals. This is incorrect as Rice is the highest produced grain in India, not wheat.

2. Rice—Wheat—Pulses—Coarse: This suggests that after rice and wheat, pulses are produced more than coarse cereals. However, in reality, coarse cereals are produced more than pulses.

3. Wheat—Rice—Coarse cereals—Pulses: This sequence indicates wheat as the highest produced grain which is incorrect considering the fact that rice is the most produced grain in India.

Lastly, option 4. Rice—Wheat—Coarse cereals—Pulses: This is the correct sequence, as rice is the topmost produced grain in India followed by wheat, then coarse cereals, and lastly pulses.