The smallest unit that retains the properties of an element is a(n)
atom
molecule
proton
compound
neutron
electron

Answer : The correct option is, Atom

Explanation :

Atom : It is the smallest unit of matter that retains the chemical properties of an element.

As we know that an atom consists of two regions.

The first region is the atomic nucleus which is present in the center of the atom and it contains proton and the neutrons in which the protons are positively charged particles and the neutrons are neutral or uncharged particles.

The second region is the cloud of electrons that means the electrons are present around the nucleus. The electrons are negatively chatged particles.

Due to the attraction between the positively charged protons and the negatively charged electrons, the atoms hold together.

Hence, the correct option is, Atom

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.