Final answer:
The correct verb form to complete the sentence is 'irá'
Step-by-step explanation:
The verb form that correctly completes the sentence is irá.
In this sentence, Alejandro is the subject and 'irá' is the appropriate form of the verb 'ir' (to go) in the third person singular form, indicating that Alejandro will go.
An example sentence using this verb form is: El próximo verano, Alejandro irá a mochilear a la montaña Cotopaxi.
Learn more about Verb conjugation in Spanish