The correct option is A Mutation
Sudden
and a heritable change in a character/ gene of an organism is mutation. Mutation
is sudden, discontinuous variation in genotype and phenotype of an organism due
to change in chromosomes and genes. In addition to recombination, mutation is
another phenomenon that leads to variation in DNA. A point mutation is a change
of a single base pair in DNA. Some mutations involve changes in whole set of
chromosomes (polyploidy) or change in a subset of chromosome number
(aneuploidy). So, the material for organic evolution is mutation because
mutation leads to evolution.