All the statements are true about mutations except
a) mutations must be present in parents and then passed to offspring.
b) mutations can be positive and produce organisms with improved traits.
c) mutations can be fatal to the organism that has a mutation, if the mutation is in a critical gene.
d) mutations can be silent, and not affect the organism that has them, if the mutation is in a non-critical area.

The correct answer is- A) Mutations must be present in parents and then passed to offspring.

Mutation can be described as the permanent change in the genetic material ( DNA) of an organism. It can be beneficial or harmful to the life form. Mutations can be heritable ( that is passed from one generation to the next) or non inheritable ( not passed from parents to offsprings).

A silent mutation ( change in the nucleotide sequence without any change in the amino acid sequence) that does not show any observable effects in the phenotype of the organism.

Thus, only option A) is not true about mutation.