Noah must pay $44 up front, monthly; this is represented by the y-intercept of the straight line graph of the cost function. He pays $5 per gigabyte. The total monthly cost to him is
C(x) = $44 + ($5/gigabyte)x which must be less than $50/month. Symbolically, this is
$44 + $5x < $50, which is the same as the last of the the four given possible answer choices.
