Answer :
A proton consists of 2 up quarks and 1 down quark.
A neutron consists of 1 up quark and 2 down quarks.
A deuterium nucleus consists of one proton and one neutron, so its quark composition is (3) 3 up quarks and 3 down quarks.
A neutron consists of 1 up quark and 2 down quarks.
A deuterium nucleus consists of one proton and one neutron, so its quark composition is (3) 3 up quarks and 3 down quarks.