A by reinforcing the idea that the egg becoming the most liked post on Instagram was a surprise
The first sentences show that an egg won for the most liked post and the words "just an egg" indicate a slight surprise. The next two sentences describing the egg winning as madness furthers this element of surprise. The other options are incorrect because even though the phrase "just an egg" can be used to infer that the photo was simple is not enough to show that any photo that is the most liked is a simple photo. There is also no historical context given in these lines and the lines do not describe how people were affected.