Final answer:
The correct definite article for the noun 'niño' in Spanish is 'el'.
Step-by-step explanation:
The correct definite article for the noun 'niño' in Spanish is el.
The definite article in Spanish agrees with the gender of the noun. Since 'niño' is a masculine noun, the corresponding definite article is 'el'.
For example, you would say 'el niño' to mean 'the boy' in Spanish.
Learn more about Definite articles in Spanish