Answer: The correct answer is- A) Incomplete dominance.
Incomplete dominance means neither of the allele ( that is dominant and recessive allele) shows its phenotype complelety. In other words, no allele is completely dominant and a heterozygous condition produces an intermediate phenotype that lies between a dominant and a recessive trait.
As per the question, the phenotype of parents are - curly hair and straight hair.
As child expresses and intermediate phenotype that is wavy hair, therefore it is an example of incomplete dominance.
