Answer:
Fact
Explanation:
Facts are statements that are inherently true. They are supported by statistics and hard evidence. Opinions, on the other hand, are statements of someone's point of view of something or their belief. They aren't necessarily "true" per se, but they represent that person's perspective.
Here, the sentence is "Instagram has become a widely used social media app in the United States". This is a fact because it can be backed by hard evidence. It's not an opinion because people can't exactly dispute something like this.
Thus, it is a fact.
