The correct answer is B. Tissues.
Cells with similar markers stick together and function as tissues. A tissue is a group of cells that are similar in structure and function. Tissues are the basic building blocks of organs, which are the basic functional units of an organism.
Organs are made up of different types of tissues that work together to perform a specific function. For example, the heart is an organ that is made up of muscle tissue, connective tissue, and epithelial tissue. The muscle tissue in the heart contracts to pump blood, the connective tissue provides support and structure, and the epithelial tissue lines the inside of the heart and helps to prevent infection.
Systems are made up of different organs that work together to perform a specific function. For example, the digestive system is made up of the mouth, esophagus, stomach, small intestine, large intestine, and rectum. These organs work together to break down food and absorb nutrients.
Organisms are made up of different systems that work together to maintain life. For example, the human body is made up of the digestive system, respiratory system, circulatory system, nervous system, endocrine system, immune system, and reproductive system. These systems work together to keep the body functioning properly.