The answer is; A
Since the earth was formed approximately 4.6 billion years ago, the heat that was generated during its formation has not been entirely lost. Some of the heat is still insulated inside the earth (below the crust) and is only lost very slowly over time. In addition, the earth hardly cools because the lost heat is replenished by the heat from radioactive elements that decay in the earth’s core. Some of these radioactive elements are uranium.
Answer: ice+ dust
Explanation: they are composed of dust, rock and ice.
The homeostatic control system component which transmits the
response is called the receptor.
To add, the receptor is <span>an organ or cell able to respond to light,
heat, or other external stimulus and transmit a signal to a sensory nerve.</span>
The control group is the one that won't receive fertilizer.