Which of the following best describes conduction?

A. Conduction is the transfer of thermal energy using waves through space or through a material medium. on 1
B. Conduction is when thermal energy is transferred by the motion of liquids or gases of varying densities.
C. Conduction is the movement of thermal energy directly from one particle to another particle through contact.
D. Conduction is the increase in thermal energy created by the restriction of the movement of energy particles.

Working alone at its constant rate, pump x pumped out ¼ of the water in a tank in 2 hours. then pumps y and z started working and the three pumps, working simultaneously at their respective constant rates, pumped out the rest of the water in 3 hours. if pump y, working alone at its constant rate, would have taken 18 hours to pump out the rest of the water, how many hours would it have taken pump z, working alone at its constant rate, to pump out all of the water that was pumped out of the tank? a) 6b) 12c) 15d) 18e) 24