Explanation:

- Option 1: "withdraws" is the present simple tense in third person singular. It's used when the subject is "he," "she," or "it." Not appropriate here as "you" is the subject.

- Option 2: "withdrew" is the past simple tense of "withdraw." It indicates an action that happened in the past. Not suitable since the context here is present or future possibility.

- Option 3: "withdraw" is the base form of the verb. Suitable when discussing the ability or permission to withdraw money now or in the future, which fits the context here perfectly.

- Option 4: "withdrawn" is the past participle form used in perfect tenses or passive voice. Not right for this sentence.