Which of the following is not an example of an irrational belief?

I must get an A in this class or l$\text{'}$m not smart.

I did not do well on this test so I am going to study harder so I can do better next time

I got a B in this class and I always get A$\text{'}$s$.$ My life is over!

My instructor doesn't like me and that's why I$\text{'}$m failing.