A cell grows and multiplies mainly through

The process by which body cells expand in size and increase in number is called mitosis. In this type of division one parent cell produces two identical daughter cells each containing the same number of chromosomes. It is vital for growth repair and replacement of worn out tissues in living organisms. Unlike meiosis which produces gametes with half the chromosome number mitosis preserves genetic stability. This makes mitosis fundamental for maintaining proper functioning of multicellular organisms. Hence the phenomenon described in the question is mitosis which corresponds to option B.