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8. Draw structural formula for the molecules indicated below. For A and B, be sure to show the correct arrangement about the double bonds. For C and D, be sure to show the correct three dimensional arrangements about the stereogenic carbon center. a) (Z)- 1 -bromo-2-methyl-1 -butene b) (2E, 4Z) - 2 - bromo-5-chloro-2,4-hexadiene also called: (2E, 4Z) - 2 - bromo - 5- chloro-hexa-2,4-diene c) (3R)-2,3-dimethylpentane d) (3S)-3 -bromo-3 -chloro-1-hexene