Let marked price =4p, cost price=3p
Let discount percentage offered before it was sold =3q, profit(loss) percentage=4q.
Therefore (4p)-(4p)(3q)/100 = selling price................................................(1)
Assume it as a profit case then (selling price - 3p)/3p * 100 = 4q...............................................(2)
Now substitute 1 in 2 we get
{(4p) - (4p)(3q)/100 - 3p}/3p * 100 = 4q
{p(1- 12q/100)}/3p * 100 =4q
q = 100/24
In solving as no negative values are obtained our assumption of profit is true.......and finally value of 4q = 4*100/24 =50/3% profit
Option C is correct.