Answer: When electricity flows through it.
Explanation:
The electromagnet exhibits magnetic properties only as soon as current flows through the nucleus. Namely, the electric current in the space around the electrical conductor through which it passes creates a magnetic field. Unlike a permanent magnet, which has a permanent property of magnetism, the electromagnet is a temporary magnet because the magnetic field also disappears when the current ceases.
D, the plant takes Solar/Light energy and converts it into chemical energy.
B. for growing vegetation and crops, because it says that, "The newly deposited soil nutrient rich and would be good." so it's good for the crops.
