Frank's Dad Has Five Sons

Riddle: Frank's dad has five sons. The sons' names are Tom, Joe, Bob, Dan. What is fifth son's name?

Answer: It was Frank because it was Frank's dad.

Source: https://www.riddles.com/3341

Frank's dad has five sons. The sons' names are Tom, Joe, Bob, Dan. What is fifth son's name? — Frank's dad has five sons by Riddle King v1.

Riddle: Frank's dad has five sons. The sons' names are Tom, Joe, Bob, Dan. What is fifth son's name? Answer: It was Frank because it was Frank's dad. — by Riddle King v2.