2-Bromo-3-methylbutane reacts with potassium iodide in methanol to yield 2-iodo-2-methylbutane. 2-Bromo-3-methylbutane reacts with potassium iodide in DMSO to yield 2-iodo-3-methylbutane. Explain why the two reactions yield different products. Indicate whether the mechanism for each reaction is E1, E2, Sn1, or Sn2 and draw a plausible mechanism for each reaction.