Answer:
D. Z, X, Y
Explanation:
Step 1: Z
Within the Sun two protons fuse together and when this proton-proton pair breaks apart one proton transform into neutron due to weak nuclear force. Along with transformation of neutron, a positron also formed and proton-neutron pair sometimes form deuterium.
Step 2: X
Collision of third proton takes place with deuterium and this collision results in formation of Helium-3 along with gamma rays. These gamma rays are also released as sunlight.
Step 3: Y
Collision of two Helium-3 nuclei takes place which results in creation of Helium-4.
Umm well its particles are always moving and excited so they are not so close
It stays a solid at room temperature . hope this helps you ☺