(b) The train now travels with a constant speed of 24 m/s along a straight honzontal track The total force opposing the motion due to friction and air resistance is 72 - 10^N (0) By considering the work done by the train's engine in 10s, calculate its output power powers 12]
(10) The train begins to travel up a slope Explain why the power of the train's engine must be increased to maintain the speed of 24 m/s​

double the distance = divide strength by 4

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.

your answer is c! hope this : )