Ellas son (fuertes).
Because it’s in plural.
I’m a Spanish fluent .
This is the right answer #3
This is correct. This is a reflexive verb that you are doing to yourself. This translates to, "Normally I brush the hair". If it was something like "Normalmente me cepillo el pelo de Anna" it would be incorrect because you are doing it to Anna, not yourself.
The answer to this blank is trabaja
Elsa trabaja tarde los fines de semanas
Translation: Elsa works late on the weekends