Of the following statements which is/are correct?

(A) During incomplete dominance, modified allele is the dominant allele

(B) In polygenic inheritance, the effect of each allele is additive

(C) A gene is called pleiotropic when it exhibit multiple phenotypic expression

(D) Mutation means alteration of DNA sequence which ensures change only in the phenotype of an organism

Choose the correct answer from the options given below: