Final answer:
In Spanish, 'hablar' (to speak) is an example of an AR verb, indicated by its '-ar' ending in the infinitive form.
Step-by-step explanation:
The answer to which of the following is an example of an AR verb in Spanish is a) Hablar (to speak). Spanish verbs are classified into three categories based on their endings in their infinitive forms: AR, ER, and IR. The verb hablar ends in -ar, which makes it an AR verb. On the other hand, comer (to eat) and escribir (to write) are examples of ER and IR verbs, respectively, due to their endings.