Select the pair of correct statements out of the four (a-d) given below about chromosomal theory of inheritance a) Chromosomes as well as genes occur in pairs b) Two alleles of a gene pair are located on non-homologous sites on homologous chromosomes c) Sutton and Boveri argued that pairing and separation of a pair of chromosomes would lead to the segregation of a pair of factors they carried d) Thomas Hunt Morgan proposed the chromosomal theory of inheritance The correct statements are