In the given sentence, "Pido que mi madre" is the main part of the sentence, meaning "I ask my mother." The next part should be in the subjunctive mood because it follows a verb of influence (pedir que - to ask that) indicating a desire or request.
Option a, "hable," is in the correct form for the subjunctive mood. It translates to "talk" or "speak," which fits the context of the sentence, making it the most appropriate choice for completing the sentence correctly. This would result in the complete sentence: "Pido que mi madre hable con mi tía."
On the other hand, option b, "habla," is in the indicative mood which is not suitable in this context after the verb "pido que" because the subjunctive mood is required.
Therefore, the correct answer is option a, "hable."
