why is extra vitamin C excreted in urine from the body but vitamin A in excess is retained in the body

Vitamin C is water-soluble and not stored in your body

In contrast to fat-soluble vitamins, water-soluble vitamins do not get stored within the body. Instead, the vitamin C that you consume gets transported to your tissues via body fluids, and any extra gets excreted in urine ( 1 ).

where are the choice options?

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8