En la maduración del cerebro que inicia desde la nuca hasta la frente la última área que madura es la corteza prefrontal que ayuda a calibrar riesgos, se ocupa del control de impulsos, el juicio y toma de decisiones.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

passive transport is a movement of biochemicals and other atomic or molecular substances across cell membranes without need of energy input. unlike active transport, it does not require an input of cellular energy because it is instead driven by the tendency of the system to grow in entropy.

so, according to what that says, i believe it's hypertonic and hypotonic.

good luck!