Baryons consist of three quarks

Steps:

• Identify that quarks form composite particles called hadrons.
• Classify hadrons: baryons have three quarks, mesons have a quark-antiquark pair.
• Note leptons and antiquarks are fundamental, not made of quarks.
• Compare quark counts: baryons have the most at three.

Why B is correct:

• Baryons are defined in the quark model as bound states of three quarks, such as protons (uud) and neutrons (udd).

Why the others are wrong:

• A. Antiquark is a fundamental antiparticle, containing zero quarks.
• C. Lepton is a fundamental particle like electrons or neutrinos, with zero quarks.
• D. Meson consists of one quark and one antiquark, totaling one quark.

Final answer: B