An optically-active compound A (C₁₀H₁₆) reacts with H₂ in the presence of Pt to afford B and C, both having the formula C₁₀H₂₀ and both optically inactive. A undergoes ozonolysis and reduction with (CH₃)₂S to give optically-active diketoaldehyde D and compound E. What are the structures of A, B, C, and E. Explain and illustrate. What is the R,S configuration of A? [Note: B and C are arbitrarily assigned. Here are some hints: What is the degree of unsaturation in A, B, and C? What is E -- do the math? How many ways can D be reassembled retrosynthetically to produce olefins that upon reduction give non-optically active compounds?]