A. Harmless
B. Deceptively harmful
C. Beneficial
D. Transparent
Answer: Deceptively harmful
A. Harmless
B. Deceptively harmful
C. Beneficial
D. Transparent
Answer: Deceptively harmful
Additional Information: 'Insidious' refers to something that proceeds in a gradual, subtle way, but with harmful effects.
Subjects: Word Meanings, Vocabulary