Answer
2-pentene exhibits cis trans isomerism
Work Step by Step
If we look at the structure of 2-pentene, we see that there are two groups bonded with one of the double bonded C atom which are methyl group and hydrogen. Also, the other double bonded C atoms have ethyl group and hydrogen that are bonded with the other double bonded C. So, two same groups are attached with two double bonded C atoms which can be on the same side (cis isomer) or on the opposite side (trans isomer).
Look at the below figure where the same groups are marked with dotted circle for better understanding of cis and trans isomer.
