Match the terms in Column I with their description in Column II and choose the correct option:
Column I
Column II
(a) Dominance
(i) Many genes govern a single character
(b) Codominance
(ii) In a heterozygous organism only one allele expresses itself
(c) Pleiotropy
(iii) In a heterozygous organism both alleles express themselves fully
(d) Polygenic inheritance
(iv) A single gene influences many characters

Dominance refers to the ability of one allele to mask the expression of another allele of the same gene present together in a heterozygous individual. When both recessive and dominant traits are expressed in a heterozygous genotype, it is codominance. This means that none of the factors is recessive but both can express themselves irrespective of their presence in homozygous or heterozygous condition. Pleiotropy is the condition where a gene has its own independent effect but also modifies the expression of a completely different gene quantitatively. A polygenic trait is the one that is governed by more than one gene where the dominant allele of each gene expresses only a part of the trait and the full trait is expressed only in the presence of dominant alleles of all multiple genes. The correct answer is B.