Simple...
when you say masculino y femenino it literally is talking about the verb...
there's two ways to conjugate verbs
One might say: Ella es una doctora.. (she is a doctor)
or might say: El es un doctor (He is a doctor)
Notice the difference?
Then we may get more trickier-->>
La sal
La miel
La nieve
La noche
And so on, and so forth...
Thus, your answer.