out of these 4 sentences, which one includes a subordinating conjunction. One common, and very persuasive, type of advertisement is known as the association ad. Ads that tell a story are found most often in commercials, as a story relies on multiple images and a sequence of events. For example, one stain removal product proves to be superior to another by removing a seemingly impossible stain from a shirt. One common, and very persuasive, type of advertisement is known as the association ad.​

Ads that tell a story are found most often in commercials, as a story relies on multiple images and a sequence of events.

Explanation:

Subordinating conjunctions are words that are used to link a dependent clause to an independent clause. In the selected sentence above, 'as,' is the subordinating conjunction that shows cause and effect. In this sentence, the first clause,

Ads that tell a story are found most often in commercials

is the independent clause because it can stand alone and still make a meaning.

The second clause which begins with the subordinating conjunction, 'as', is the dependent clause because it relies on the first clause to make a complete meaning. It  serves as a clause that indicates purpose.