Answer:C: the number of the noun
Explanation:
When we use possessive adjectives like tu, tus, mis etc we are matching them with the number of the noun, plural or not, example,
"Tus calcetines"
TUS is a plural possesive adjective and calcetines is the plural noun of calcetin
"TU calcetin"
TU is singular, and calcetin is a singular noun
D.Hay porque hablo español
Where is Javier from? Where does he live? When doesn't Javier swim? Where does Javier go on Mondays? What does Javier study? Where does Javier go after his classes?where do Javier and his friends go on Saturdays? What does Javier see in the museum?
Yo hablo (hablar) is the correct answer