Answer
Four geometrical isomers of sorbic acid are written below marked as I, II, III & IV. Among them, I & II have the same molecular formula and structure but different in orientation i.e. I is trans and II is cis isomer. III & IV have the same molecular formula and structure but different in orientation i.e. III is trans and IV is cis isomer.
Work Step by Step
If two same groups attached with two double bonded carbon atoms are present on the same side, then the isomer is called cis isomer.
On the other hand, if two same groups attached with two double bonded carbon atoms are present on opposite side to each other, then the isomer is called trans isomer.
See below figure.
