Which of the following best describes conduction?

A.
Conduction is the movement of thermal energy directly from one particle to another particle through contact.

B.
Conduction is when thermal energy is transferred by the motion of liquids or gases of varying densities.

C.
Conduction is the transfer of thermal energy using waves through space or through a material medium.

D.
Conduction is the increase in thermal energy created by the restriction of the movement of energy particles.

A.

Conduction is the movement of thermal energy directly from one particle to another particle through contact.