Don’t worry, I will stand . . . . . . . . you if you get into trouble. A. for B. out C. by D. up

The correct answer is: up.

The word “up” means to support or defend someone. In this context, the speaker is saying that they will support the listener if they get into trouble.

The other options are incorrect because they do not have the same meaning as “up”.

• “For” means to be in favor of someone or something.
• “Out” means to be exposed or revealed.
• “By” means to be accompanied by someone or something.

I hope this helps!