Treating (CH3)3C-Cl with a mixture of H2O and CH3OH at room temperature would yield: A) CH2=C(CH3)2 B) (CH3)3COH C) (CH3)3COCH3 D) All of these choices. E) None of these choices.

All of the choices.

Explanation:

As the reaction is involving with a mixture of H₂O and CH₃OH, these two reagents can work as nucleophyle of the reaction. Both of them, are polar and promoves a Sn1/E1 reaction. When it reacts with water it will produce product B); it will form product C) when it reacts with methanol, and product A) will be formed when the reaction undergoes an E1 reaction.

In this case, the only way to show you this, it's doing the mechanism of reaction for each product. Picture attached show the mechanism for the formation of all these products.

that's what i got you can count the number of atoms