The answer to this question is B because the initial start up cost is $200, and then there is a $50 per month charge. The x represents the amount of months you would want the phone for. If you only wanted the phone for 1 month, x would be equal to 1. If you wanted the phone for 7 months, x would be equal to 7.
The answer would not be A unless the $50 was the start up cost and the $200 was the monthly cost. This is because it is 50 + 200x which suggests that $200 is the monthly fee and not $50.
