Out of the public’s interest in the details of and conflicts in other

To understand this question in its logical perspective, one needs to appreciate that the shows themselves create the interest by virtue of their sensational nature and therefore people throng to see them. Therefore, it is clear that the shows entice people. Then a demand emerges and the commercial people step in to cash in on the ready-made boom to make easy money. Therefore, the booming market is the end of the chain and not the beginning.
If this tenet is clear, then this can be easily solved. Here the verb has to be plural either -are bringing or a simple present tense bring. It is now the importance of the increasing frequency can be realized. It a frequently changing one means that it is a dynamic factor and an on- going affair. What better way could be there than to describe in a progressive tense—namely, are bringing. Please also note that choice B meticulously abides by the touch rule of relative pronoun. Therefore, B is the best IMO.
Kaplan’ choice of D as the official answer is understandable, considering Kaplan’s fancy for gaining popularity more through controversies than through logic

how can market bring regular people onto the television screen.. the shows are bringing regular people onto the television screen