Total charge from quark electric charges

Steps:

• Up quark charge is +2/3 e; charm quark charge is +2/3 e.
• Two up quarks contribute 2 × (+2/3 e) = +4/3 e.
• Add charm quark: +4/3 e + 2/3 e = +6/3 e = +2e.
• Particle charge is sum of quark charges.

Why D is correct:

• Baryon charge equals sum of constituent quark charges per the quark model.

Why the others are wrong:

• A: Matches three down quarks (-1/3 e each, total -e, but doubled negatively).
• B: Matches proton (two up, one down: +1e).
• C: Matches antiproton or negative pion charge.

Final answer: D