Sound cannot travel a) a vacuum b)space c) the atmosphere d) a and b only

d.) a and b only

This is because sound needs a medium to travel.  It can travel in a solid (the fastest) and air for example.  Sound waves cannot propagate through a vacuum and since space is a vacuum the answer is a and b only.

it is easily magnetized.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be