Question

how do plants obtain the energy they need?
by eating other organisms
by absorbing energy directly from soil
by using light energy from the sun to make food molecules
by breaking down minerals

Explanation:

Plants are autotrophs. They use the process of photosynthesis. In photosynthesis, plants take light energy from the sun (usually sunlight), carbon dioxide from the air, and water. Through a series of chemical reactions in chloroplasts, they convert these into glucose (a food - molecule) and oxygen.
Eating other organisms is a characteristic of heterotrophs (like animals). Absorbing energy directly from soil is not a valid way for plants to obtain energy as soil mainly provides minerals and water (not energy in a usable form for energy acquisition in the sense of the question). Breaking down molecules (like in cellular respiration) is a process to release energy from already - made food molecules (like glucose), but the initial acquisition of energy (to make those food molecules) is through using light energy from the sun.

Answer:

By using light energy from the sun to make food molecules.