In a formal setting we need to listen carefully analyse the situation and then speak our minds.Where as in an informal setting we can interrupt in between and can speak our minds. In a formal setting we need to be formally dressed too where as in an informal setup we can wear casuals.
The right answer for this is B.No juegues
I think what your looking for is esta haciendo. I'm sorry if I'm wrong.
The Profesor's book of education for math