Which of the following sentences includes a subordinating conjunction?
A. If we hear someone endorsing the product, we might want to buy it.
B. Advertising goes down the street with us; it's on trains, planes, and buses.
C. It shouts at us at sporting events from the banners on display and the electronic scoreboards.
D. The speaker may be holding the product, tasting it, wearing it, showing before and after pictures.