Answer:
1 → D
2 → C
3 → B
4 → A
Step-by-step explanation:
Benzoyl peroxide is used to treat mild to moderate acne.
Nitrous oxide is used in surgery and dentistry as an anesthetic.
Acetylsalicylic acid is used in medications to treat inflammation , fever and pain.
Barium sulfate is CT-scan and other radio-logical examinations .Barium sulfate coats the inner lining of esophagus, stomach, intestines which helps in developing clear images of these internal body parts during x-rays.