A) It's a waste of time to play music for pets because animals obviously can't understand the songs' words.
Explanation: If we look at the other statements, we can see that they use facts, and are nonobjective. We can see this when it shows a poll, (C) which had over 5000 poll answers, and it gave us the data of 80% thought their pets liked the music. Another statement (D) tells us that dogs don't like a type of music (Heavy metal) because the sounds used seem threatening to dogs. And in (B) it shows that subscribers need to answer a survey about their pet's personality. All of these are statements, except for A, which is an opinion. (Hope this helps)
