Will give brainliest
consider a girl that has a mass of 55.0 kg and is standing on the floor, how much supporting force does the floor have?
at least 55 kg up
at least 55 kg down
at least 539 n up
at least 539 n down

Mass of girl =55kg
acceleration due to gravity =9.8m/s^2

So, the force she is applying on the floor must equal
55× 9.8 N
(Because force =mass ×acceleration)
=539N

Now, according to newton's third law the floor must be applying the same force on the body in the opposite direction.
So the force applied here by the floor is 539N upward.

Option "C" is the correct one.