Hint: The genetic combination of organisms is a highly precise and well-regulated process. Any error during the whole process can result in genetic abnormalities, and sometimes can be transmitted from one generation to the other.
Complete answer: Any change, physical or chemical, that can alter the position as well as the nature of the nucleotides is known as Genetic mutations. Mutation can range from a change in a single nucleotide to the loss or addition of a whole fragment. The process of genetic mutations is reversible, and once occurred, it cannot be reverted to the normal stage. Considering the other given options: A.It is not reversible since the changes cannot be taken back to normal, unless in certain conditions such as back or reverse mutations. Thus it is not the right option. C. The process is also not partially reversible. Thus it is not the right option. D. The mutation is not a continuous option, but a spontaneous process, that occurs at a specific point or base pairs. Thus it is not the right option.
Therefore, by considering all the given options, the most appropriate one is B. That is the process of genetic mutation is irreversible.
Note: There are broadly two types of genetic mutations. They are Hereditary and acquired mutations. Hereditary mutations can be passed on to the successive generation through the parents. Whereas acquired mutations occur spontaneously during the lifetime of the person. A hereditary mutation occurs to the sex chromosomes, while the acquired mutations occur in the somatic cells.