Compound A and compound B both have molecular formula C₆H₁₂. Both compounds produce epoxides when treated with MCPBA.

a. The epoxide resulting from compound A was treated with aqueous acid (H₃O⁺) and the resulting diol had no chirality centers. Propose two possible structures for compound A.

b. The epoxide resulting from compound B was treated with H₃O⁺ and the resulting diol was a meso compound. Draw the structure of compound B.