Answer:
The correct answer is A.
Step-by-step explanation:
Methane (CH4) is a tetrahedral molecule with a carbon atom bonded to four hydrogen atoms, and all the bond angles in a tetrahedral geometry are approximately 109.5°, which is closest to 120° among the given options. Option B, H−C≡C−H, represents acetylene, which has a linear geometry with bond angles of 180°. Option C, CHI3, represents iodoform, which has a trigonal pyramidal geometry with bond angles slightly less than 109.5°. Option D, O=C=S, represents carbon disulfide, which has a linear geometry with bond angles of 180°. Option E, H2C=O, represents formaldehyde, which has a trigonal planar geometry with bond angles of 120°, but it is not as close to 120° as CH4.