it would need to be a positive line so that eliminated A. also D is not it because the calories will go up, and not stay the same. this leaves is with B and C. I think that it is B because you have to start at 0. hope this helped!
The answer is 90%. You get this answer by multiplying both the numerator and denominator by 5 so 18x5=90 and 20x5=100 giving you a fraction of 90/100 and a percentage of 90%.