Final answer:
The correct verb form to complete the sentence is 'puedan' in Spanish.
Step-by-step explanation:
The correct verb form to complete the sentence is puedan. It is important to use the subjunctive form of the verb when expressing a necessity or requirement. In this case, the sentence is stating that it is indispensable for indigenous communities to have their lands, which requires the use of the subjunctive mood.
Learn more about verb forms in Spanish