Last year, construction in the city of Vonter, including the rewiring of telephone and cable lines, caused the cost of providing cable television service to homes within the city to increase by 12 percent as compared to the previous year. In response, all cable companies in the city increased the price of their monthly service to customer. Broadcast Television Cable Company has found, however, that the proportion of cable bills paid on time decreased sharply the six months after raising the price of monthly service but returned to the previous year's level by the end of the year.

Which of the following, if true, most helps to explain the change between the first half and the second half of the year in the proportion of cable bills not paid on time to Broadcast Television Cable Company?

(A) The total number of homes subscribing to cable service within Vonter increased between the first and second half of the year.
(B) Between the first and second half of the year, Broadcast Television Cable Company, unlike other cable service providers in Vonter, increased the number of channels that it offers to customers.
(C) Because Broadcast Television Cable Company provides only a premium cable package, a large portion of its subscribers who could no longer afford this package switched to another provider by the second half of the year. correct
(D) In order to attract more subscribers, all cable service providers in Vonter offered promotional sign-up packages that began in the second half of the year.
(E) The rewiring of telephone and cable lines in Vonter caused other businesses, such as telephone companies that had provided service to landlines, to suffer, and thus many workers in Vonter were laid off immediately after the construction was completed.

OA is C
What makes OA the perfect choice of answer here? I love an explanation from an Expert. Thanks in anticipation.