Baryon charge from quark charges Steps:

• Quark charges: up = +2/3 e, down/strange = -1/3 e (e = 1.6 × 10^{-19} C).
• Sum charges for A (udd): +2/3 - 1/3 - 1/3 = 0.
• Sum charges for B (uss): +2/3 - 1/3 - 1/3 = 0.
• Sum charges for C (uud): +2/3 + 2/3 - 1/3 = +1 e.
• Sum charges for D (uuu): +2/3 + 2/3 + 2/3 = +2 e.

Why D is correct:

• Total charge +2 e = +3.2 × 10^{-19} C, neither +1.6 × 10^{-19} C nor -1.6 × 10^{-19} C (quark model sums charges for baryon total).

Why the others are wrong:

• A: Forms neutral neutron (charge 0 C).
• B: Forms neutral Ξ⁰ (charge 0 C).
• C: Forms proton with charge +1.6 × 10^{-19} C.

Final answer: D