Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Frank needs to move a box by sliding it across the floor. Which two factors will most strongly affect how hard Frank needs to push the box?
The total mass of the box and the friction between the box and the floor
The weight of the box and the coefficient of friction between the box and the floor.