Answer:
ad populum (bandwagon Fallacy)
Explanation:
In an argument the use of faulty reasoning or something invalid to make a case is called a fallacy.
The statement here describes the ad populum or bandwagon fallacy.
The belief of the common masses in argument is used to make a statement. If the masses believe in something then that fact must be true even if the thing they believe in is factually wrong, is the definition of the bandwagon fallacy.