"Se usa para pensar" means (It is used to think) el cerebro means "brain". "La garganta" means "throat". "La mejilla" means "the cheek". "La cara" means "face". It is A. Hope it helps! ~Pooch ♥
Afeitarse means "to shave oneself".
Out of the words, the best fit item is "la navaja", which means "the razor".