What is not true about cell cycle ?
a. During `G_(1)` phase there is active synthesis of RNA and proteins but no change in its DNA content
b. In synthesis or S phases, each chromosome carriers a duplicate set of genes
c. During `G_(2)` phase, a cell contains double the amount ($C) of DNA present in the original diploid cell (2C)
d. In S-phase a cell doubles the original diploid (2n) chromosome number