Ben builds ladders of different heights and put the number of rungs depending upon height of any particular ladder. He uses an equation for this construction that is given by :-
r = h ÷ 0.8
where h is the height of the ladder and r is the number of rungs in that ladder.
As we increase the height of the ladder, we need more rungs. If we decrease height, we would need lesser rungs.
Thereby, the number of rungs depend on the height of the ladder. It means value of r depends on value of h.
So r is dependent variable, and h is the independent variable.
Hence, option A is correct i.e. the height of the ladder.
