I believe the answer is D.
Population because you are holding it
Answer:
Tissues
Explanation:
Tissues are organized group of cells carrying out specific coordinated functions. They are organizational structures that lies between cells and organs. A group of cells binds together using specialized proteins forming a tissue, furthermore, a group of different tissues are the building blocks for organs and plant structures creating a complete system.
The piano could only be played with 12 fingers, which is rare because humans normally have ten fingers.
2. The evolutionary process through which new species emerge
