Final answer:
The appropriate personal pronoun to fill in the blank is "les" for plural indirect object.
Step-by-step explanation:
The correct personal pronoun to fill in the blank in the sentence is les.
This is because the phrase "A los estudiantes" indicates a plural subject, and the appropriate pronoun to use for a plural indirect object is les.
Here is an example: "A los estudiantes les importa realizar bien sus estudios." This translates to "They care about doing well in their studies."
Learn more about Personal Pronouns in Spanish