Answer:
b. gene mutations.
Explanation:
The segment of DNA which can undergoes mutation is called muton and this is one of the definition of a gene. A permanent change in the DNA structure is called mutation. Mutation can affect from a single base pair to a large segment of a chromosome. The DNA sequence of a gene can be changed in a number of ways such as addition (by adding a piece of DNA), deletion (by removing a piece of DNA), and duplication in one or more nucleotide in in a DNA molecule. Gene mutations can change the function of many important proteins in the body.