Answer:
I am certain she is the best mom in the world.
Step-by-step explanation:
We can see that the writer might be a little biased when he says that his mother is the "best mom," because after all, how many moms did he have? He exaggerates. He believes that his mom is the best in the world because he believes that she did everything right. He did not have any other mother to compare her against, so he cannot prove that she is the "best mom in the world."