Nokea
The development of the disease was INSIDIOUS.
Correct Answer: D
Rationale: The term 'insidious' typically describes something that occurs gradually and subtly, often without being noticed until it has become more serious or established. Therefore, the development of the disease being insidious suggests that it was gradual, aligning best with the meaning of the word in this context. Choice A, 'momentous,' means significant or important, which is opposite in meaning to insidious. Choice B, 'sudden,' indicates something happening quickly and unexpectedly, contrary to the gradual nature of an insidious development. Choice C, 'innocuous,' means harmless or not likely to cause harm, which does not accurately reflect the negative and harmful connotation associated with an insidious disease development.