Final answer:
The appropriate preterite form of the verb organizar is organizó.
Step-by-step explanation:
The appropriate preterite form of the verb organizar to fill in the blank in the given sentence is organizó. In this sentence, the subject is La asociación de estudiantes, which is singular and third person. Therefore, the correct form of the verb in the preterite tense is organizó. This form indicates that the association organized the dance.
Learn more about Conjugation of verbs in Spanish