Ans. (B). They are complex organs made of many types of cells and tissues.
Organ culture involves development of tissues or organs, in vitro (outside the body), to restore, maintain, or improve damaged organs or tissues. Many organs and tissues are successfully grown by engineered tissues, such as skin and cartilage.
However, heart, lungs, and other complex organs have not been very successfully grown as these organs are made up of different types of tissues and cells. For examples, heart is made up of cardiac muscle tissue, skeletal tissues, and smooth muscle tissue.
It is quite tough to assemble different types of cells and tissues to make organs fully functional or reproducible.
Thus, the correct answer is option (B).
