Final answer:
The correct answer to fill in the blank in sentence (3) is 'b. Next,' as it continues the sequence of stages in a typical television ad.
Step-by-step explanation:
The correct answer is b. Next. This option best fills in the blank in a sentence (3) by indicating the sequence of the stages in a television advertisement. Let's look at how this works within the context of the given sentences about TV ads. The progression commonly used in advertisements is the establishment of a problem, the presentation of advice or a solution, and finally, the resolution of the initial problem. So after introducing the problem, the advertisers would next suggest using their product as the solution, leading to the resolution where the product’s effectiveness is demonstrated.