The quark composition of the proton and neutron are, respectively, uud and udd, where u is an up quark (charge +23e) and d is a down quark (charge −13e). There are also anti-up u¯ (charge −23e) and anti-down d¯ (charge +13) quarks. The combination of a quark and an antiquark is called a meson. The mesons known as pions have the composition π+=ud¯ and π−=u¯d. Suppose a proton collides with an antineutron. During such collisions, the various quarks and antiquarks annihilate whenever possible. When the remaining quarks combine to form a single particle, it is a:.A) ProtonB) NeutronC) π+D) π−

Option C=> π+.

Explanation:

Just as it is given in the question above, we can see that the addition or combination of proton and neutron gives what is known as QUARKS.

Quarks are not easily measured because one can not see and study a quark independently; quarks move in multiples together.

The study of Quarks is very important in physics because they relate very well with electromagnetic force, strong force, weak force and Gravitational force.

"...When the remaining quarks combine to form a single particle, it is a π+".

π+ is a meson or a pion and it contains quarks and anti-quarks too

overcharge is the right answer system