In terms of the highest pitches they can make, which list correctly orders the instrument and vocals from highest to lowest?

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.

i believe the answer would be:

d. violin, clarinet, french horn, and tuba

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s