Final answer:
The correct plural form of 'la puerta' is 'las puertas'
Step-by-step explanation:
The correct plural form of the word 'la puerta' is 'las puertas'.
In Spanish, nouns that end in -a are usually made plural by changing the -a to -as, so 'puerta' becomes 'puertas' in the plural form.
For example: 'la puerta' (the door) becomes 'las puertas' (the doors).
Learn more about Spanish plurals