Answer:
Most of the time grammar comes after 'common sense" which is inevitable. Grammar rules don't matter anymore when it comes to informal conversation. We only pinpoint grammar errors when we don't understand the statement. So the easiest way to know if the sentence makes sense is to check if in all time subject agrees to its predicate or supporting details
The answer is C because Estan tu doesn’t make sense
1. Estoy
2. Se
3. Esta
4. Es
5. Estoy
6. Soy
"Todas mis clases son Interesantes" that would be the answer