Consider the following statements on genes and chromosomes.
a. Sutton and Boveri noted that the behaviour of chromosomes was parallel to the behaviour of genes
b. The two alleles of a gene pair are located on homologous sites of non-homologous chromosomes
c. Sutton united knowledge of chromosomal segregation with Mendelian principles and called it chromosomal theory of inheritance
d. Experimental verification of chromosomal theory of inheritance was done by T.H. Morgan
Which of the above statements are correct?