Explanation
Why Correct: "Can" is a modal auxiliary verb that expresses ability, possibility, or permission, and it always appears with a main verb in a verb phrase.
Distractor Analysis: "Look" and "Take" are main verbs that carry lexical meaning—"look" denotes visual perception and "take" denotes grasping or acquiring. "Do" can serve as an auxiliary in questions, negatives, and emphatic statements (e.g., "Do you like tea?"), but in isolation it functions as a main verb meaning to perform or carry out.
Takeaway: The full set of modal auxiliaries in English is can, could, may, might, shall, should, will, would, and must; these modals do not change form for person or number and are always followed by the base form of the main verb.