$\backslash$& ball rolls down one hill and up another hill. It doesn't get as high up the second as it started out on the first hill before it stops and rolls back down. This is because

$($A$)$ mechanical energyis conserved in this problem.

$($B$)$ some of the potential energy was converted into kinetic energy.

$($C$)$ some energy was lost to friction.

$($D$)$ some energy was converted into rotationsl motion.

$($E$)$ the ball lost momentum as it rolled up the hill.