Answer:
Option A, a compound that contains carbon atoms bound to other elements
Explanation:
An organic compound is one which has at least one carbon atom that is bonded to several other atoms (may be metallic or non metallic) by a single or double bond is termed as organic compound . The most common atoms with which carbon forms bond are hydrogen, nitrogen,and oxygen.
Some common examples are -
Methane - 
Methanol - 
Hence, option A is correct
Enzymes are proteins and they control the speed of chemical reactions in your body. Without them, the reactions would happen too slowly to keep you alive.
Some break down larger molecules into smaller ones and those enzymes are in your stomach.
Answer:
Population.
Explanation:
Population may be defined as the smallest unit of ecology and the evolution might occur at the population level.
Population is the group of the organisms that belong to the particular species and lives in a specific particular habitat. The individual of the population breeds among themselves. Sometimes the individual of two different population can also breed among themselves in extreme cases.
Thus, the answer is population.
The day before or the day after.