By changing the frequency of an EM wave, the of the wave is changing. a) speed

b) phase

c) amplitude

d) energy

e) both b and d

moving ball hits still ball. mover stops, hit ball moves. momentum transfer.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.