Answer:
Option D i.e. y = 1/2 x is the correct answer.
Step-by-step explanation:
We know that when 'y' varies directly with 'x', we get the equation
y ∝ x
y = kx
where k is the constant of proportionality.
In our case, the only equation which maps in accordance with y = kx is y = 1/2x.
i.e.
y = 1/2 x
here k = 1/2
Thus, k = 1/2 is the constant of proportionality.
Therefore, option D i.e. y = 1/2 x is the correct answer.
