The correct option is B physico-biochemical studies of biomolecules
Molecular biology is the branch of biology which deals with physico-biochemical studies of biomolecules. In other words, it deals with physical and chemical processes which biomolecules undergo in and between the cells, including molecular synthesis, modification, mechanisms and interactions. The central dogma of molecular biology describes the process in which DNA is transcribed into RNA, then translated into protein. Molecular biology also plays important role in understanding formations, actions, and regulations of various parts of cells which can be used to efficiently target new drugs, diagnose disease, and understand the physiology of the cell.