Select the most appropriate antonym of the underlined word in the given sentence:

It seemed a perfectly innocuous remark.

Option 1 -> harmless is a synonym of innocuous, not an antonym.

Option 2 -> insane means mentally ill or irrational, which is unrelated to the meaning of innocuous.

Option 3 -> pernicious means harmful, destructive, or causing great damage.

Option 4 -> permissible means allowed or acceptable, which doesn't relate to the harm/safety aspect of innocuous.

Hence, Option 3: pernicious -> "Innocuous" means harmless or not likely to cause offense/injury. The antonym would be something harmful or destructive. "Pernicious" means having a harmful effect, especially in a gradual or subtle way, making it the perfect opposite of innocuous -> correct