Final answer:
The correct verb form is 'dépensent'
Step-by-step explanation:
The correct verb form to complete the sentence is dépensent.
This is because the subject 'elles' is the pronoun for a third person plural feminine noun. In French, when referring to a group of females, the verb form used is 'dépensent.'
For example, 'Elles dépensent 100 euros pour acheter des vêtements.' means 'They spend 100 euros to buy clothes.'
Learn more about French verbs