Confusing Question for Stats 
A test is made of $H_0: M= 77.4$ and $H_a: M<77.4.$ Assume you reject the null, because you did not feel like doing a hypothesis test, and you are pretty sure your alternative is correct anyway. Have you made a Type 1 error, Type 2 error, a correct decision, or a silly decision?

I keep trying to solve this using the wording but nothing is making sense to me. I’ve already tried to think the the mean is less than $77.4,$ so the $H_0$ is false. But when I got correct decision the server said it was wrong. I also don’t see an option for a silly decision in the given chart.

In my opinion that's a silly decision because Type 1 error, Type 2 error and a correct decision all assume you know both the "True" hypothesis and the stat that you are measuring. But in this case you are not measuring any stat, therefore I'd go with silly decision, which could be correct or wrong by chance your (random) guess is true or not.
I'd point you to the second comment of B.Liu for more infos
