“Konnichiwa” is the most common way to say “hello” in what language?

Trivia: “Konnichiwa” is the most common way to say “hello” in what language?

Russian
Spanish
French
Japanese

Correct Answer: Japanese

So why is this answer correct? : It’s a shortened version of “Konnichi wa gokiken ikaga desu ka?” or “How are you feeling today?”