Please choose the correct ending to complete the given sentence: Youth: [header] How to treat acne (teen boys ) [title] Use over-the-counter products that contain salicylic acid, benzoyl peroxide, and glycolic acid. [step] These ingredients are dermatologist approved for treating mild acne effectively. The best commercial products for the treatment of acne will contain one or a combination of these three ingredients.

Ending1: However, some people can be allergic to these ingredients or develop dry or irritated skin due to these ingredients. Talk to your dermatologist if you are concerned about having an allergic reaction to any of these ingredients. Ending2: Follow the recommended amounts based on skin type, age, and other factors. Not all products containing other ingredients are approved for treating acne, which may seem obvious. Ending3: [substeps] Benzoyl peroxide is effective for 20 to 25 days, and benzoyl peroxide is useful for six to eight days. Benzoyl peroxide can cause irritation, redness, and swelling in sensitive areas. Ending4: [substeps] Lanolin is a brand of skincare that's used to treat acne mostly on your face and scalp. It's best to avoid products with salicylic acid as they will cause the acne to spread.

Answer format: ending1/ending2/ending3/ending4