Draw the main organic products of the reaction. Indicate the stereochemistry, including all hydrogen atoms, at each stereocenter. Omit byproducts such as salts or methanol.

See explanation below

Explanation:

The question is missing the innitial structure. However, I found it on another place, and picture 1 shows the innitial product and conditions. Picture 2 shows the mechanism and products of this reaction.

According to picture 1, we have a strong base (CH3ONa), so, carbocation intermediate would be imposible. This only can be done in acidic conditions and we have a base. So, we can only have a Sn2 and E2 reaction. It can be either of the two products, but the main product would be the E2 product, because the innitial structure presents steric hindrance, so the elimination would be easier than the substitution. However, in picture 2 you have the mechanism for both of them.