The correct option is A biotechnology
Biotechnology involves the various techniques that use live organisms, or their enzymes to produce products that are useful to humans in some way.
Products such as wine, bread and curd are obtained with the help of microbes. The practice of producing such products can also be considered as a form of biotechnology. But, in a stricter sense, biotechnology refers to those scientific processes that use organisms that are genetically modified to produce products efficiently and on a large scale.
In vitro fertilisation, gene synthesis, developing DNA based vaccines, and using gene therapies to correct defects in DNA are all part of biotechnology.
Molecular biology deals with the study of the chemical structures and processes of biological phenomena that involve the basic units of life.
Biochemistry is the branch of science that deals with exploring the chemical processes within and related to living organisms.
Microbiology refers to the study of all living organisms that are microscopic, too small to be visible to the naked eye. This includes bacteria, archaea, viruses, certain fungi, prions, protozoans and algae, collectively known as 'microbes'.