DNA carries all of the information for your physical characteristics, which are essentially determined by proteins. So, DNA contains the instructions for making a protein. In DNA, each protein is encoded by a gene (a specific sequence of DNA nucleotides that specify how a single protein is to be made).
Answer:
(c) Inherited a mutation in a gene required for mismatch repair
Explanation:
Gene mutations are occasional changes that occur in genes, that is, the procedure by which a gene undergoes a structural change. Mutations involve the addition, deletion or substitution of one or a few nucleotides of the DNA strand. Mutation provides the emergence of new forms of a gene and, consequently, is responsible for gene variability.
It is common for several members of the same family to have the same genetic mutations, as the gene affected by the mutation may condition a trait that DNA cannot repair. An example of this is the family shown in the question above, where several people were diagnosed with the same type of cancer while still young. What probably happened in this family was that people diagnosed with cancer inherited a mutation in a gene needed to repair incompatibility.