The Viral Riddle That is Driving the Internet Crazy: Can You Solve It? results in the first comment
The Statement: “What” is the father’s name.The Punctuation Trick: By replacing the period with a question mark, the creator of the riddle tricks your brain into looking for a hidden puzzle, when they actually already gave you the answer in the first word of the sentence.
So, if you take the riddle literally: The father’s name is “What.”
Alternative Interpretations: The “What” vs. “What?” Debate
Of course, the internet loves a debate, and this riddle has sparked two major schools of thought in the comments: