Which of the following is the functional unit of body?

The correct answer is Cell

Explanation:

• The cell is the basic structural, functional, and biological unit of all known living organisms.
• It is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life".
•  It carries out all necessary functions of life, including growth, metabolism, and reproduction.
• They also contain the body's hereditary material and can make copies of themselves.

Fig: Plant Cell

Other Options:

• Mitochondria: Often referred to as the powerhouse of the cell, mitochondria are organelles that generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy. 
• Cytoplasm: This is the jelly-like substance within the cell membrane that contains all organelles and cell parts. 
• Spleen: The spleen is an organ involved in filtering blood and is part of the immune system.