What’s the answer i need a little help

Answer: the answer is B
Step-by-step explanation: I worked the equations out by using 2 points form the graph. First i plugged in point (2, 100), x=2 and y=100
100= 50 times 2 which is true
The second point i used (5, 250) and once i plugged it in it was true
Conclusion: B is the correct answer, just put coordinates that are on the points into the equation.