What is the correct way to say "the serious boy" in spanish?

la seria chica
el serio chico
el chico serio
la chica seria

The masculine is 'el' not 'la', so it's not the first or the last answer.
Adjectives go after nouns in spanish, so the answer is 'el chico serio.'

C. El chico serio.
In spanish you put the noun then the adj.

Translated~ maria: no andrea, i'm not bad. i'm not sad either.andrea: what? maria: i'm fine but i'm very hot.(rephrase the sentence)  you: i'm excited (or excited)andrea: excited (or excited). what? i do not understand.tener = to have    estar= to be