What is not true about cell cycle ?

a) During G₁ phase, there is active synthesis of RNA and proteins but no change in its DNA content

b) In synthesis of S phase, each chromosome carries a duplicate set of genes

c) During G₂ phase, a cell contains double the amount (4C) of DNA present in the original diploid cell (2C)

d) In S phase, a cell doubles the original diploid (2n) chromosomes number