Aman stands on a platform that is rotating (without friction) with an angular speed of 1.0 rev/s; his arms are outstretched and he holds a brick in each hand. the rotational inertia of the system consisting of the man, bricks, and platform about the central vertical axis of the platform is 6.0 kg·m2. by moving the bricks the man decreases the rotational inertia of the system to 2.0 kg·m2.?

Explanation:

Given

angular velocity

Combined moment of inertia of stool,student and bricks

Now student pull off his hands so as to increase its speed to suppose rev/s

After Pulling off hands so final moment of inertia is

Conserving angular momentum  as no external torque is applied

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.