Which of the following may be separated by ordinary physical methods? Select one: O (R)-3-bromo-1-butene and (S)-3-bromo-1-butene (2R,3S)-1,2-dibromobutane and (2S,3R)-1,2-dibromobutane cis-2-bromo-2-butene and trans-2-bromo-2-butene (R)-2-bromobutane and (S)-2-bromobutane ) Clear my choice