Option 1 states that only lipstick is correctly matched with the unwanted or controversial chemical, lead. Lipstick can contain traces of lead but this option neglects the other potential matches.

Option 2 suggests that only soft drinks and Chinese fast food are correctly matched with brominated vegetable oils and monosodium glutamate respectively. Soft drinks sometimes use brominated vegetable oils, and monosodium glutamate is commonly used in Chinese fast-food. However, this option excludes the fact that lipstick can contain traces of lead.

Option 3 claims that only lipstick and Chinese fast food are correctly matched with lead and monosodium glutamate respectively. While this is true, the option leaves out that brominated vegetable oils can be found in soft drinks.

Option 4 states that all the given pairs are correctly matched. Given that lipstick can contain traces of lead, soft drinks can contain brominated vegetable oils, and monosodium glutamate is commonly used in Chinese fast-food, the correct answer is indeed option 4.