Proton consists of:: (A) 2 up quarks + 1 down quarks, (B) 2 up quarks + 2 down quarks, (C) 1 up quarks + 2 down quarks, (D) 1 up quarks + 1 down quarks
Answer is A. Protons are spin-½ fermions and are composed of three valence quarks, making them baryons (a sub-type of hadrons). The two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons.