Which of the following pairs are quarks and antiquarks?

Baryons and mesons are the correct answer because both are composite particles made up of quarks and antiquarks.

Baryons, such as protons and neutrons, are made of three quarks. In contrast, mesons are formed from a quark and an antiquark pair. This pairing is fundamental to the structure of these particles, as quarks hold fractional electric charges and have strong interactions mediated by the strong force, while antiquarks are the antiparticles of quarks, possessing opposite charges and properties.

Understanding that baryons contain multiple quarks and mesons consist of a combination of a quark and an antiquark is essential for grasping how subatomic particles interact and form the matter we observe. This knowledge also illustrates the fundamental classification of matter in particle physics, highlighting the roles of both quarks and antiquarks in the composition of different types of particles.

The other options do not indicate a relationship between quarks and antiquarks. Protons and electrons belong to different families of particles (baryons and leptons, respectively), while leptons and quarks are distinct classes that do not form pairs like quarks and antiquarks. Lastly, neutrons and positrons also represent different categories, with neutrons