The plant from which sugar can be obtained is ___________.

The correct option is A

sugarcane

The correct option is A.
Explanation of the correct option:

1. Sugar is obtained from sugarcane plants.
2. Sugar is synthesised in the leaves of the sugarcane plant through the process of photosynthesis.
3. The juice of sugarcane is heated and filtered that undergoes a series of crystallisation to produce crystals of raw sugar.

Explanation of the incorrect option:
Option B:
Wheat is one of the oldest and the most important cereal crops that is obtained from the genus of Triticum.
Option C:
Rice is an edible starchy cereal grain obtained from the genus of Oryza.
Option D:
Soybean is one of the most important legume crops in the world and is obtained from the seeds of the plant

Final answer:
The plant from which sugar can be obtained is sugarcane.