The major isolated organic product of the reaction shown (c) a trans-alkene. Therefore, (c) a trans-alkene is correct.
Platinum and palladium are both catalysts for the hydrogenation of alkenes.
In the presence of one of these catalysts, hydrogen will add to the alkene molecule in a syn fashion, meaning that the two hydrogen atoms will add to the same side of the alkene double bond.
This results in the formation of a trans-alkene.
The other answer choices are incorrect:
(a) An alkane with an arene attached is not a possible product of the reaction.
(b) A cis-alkene is not the major product of the reaction, because hydrogen adds to alkenes in a syn fashion in the presence of platinum or palladium catalysts.
(d) An alkene that is neither cis- nor trans- is not possible, because all alkenes are either cis or trans.
(e) A different product or a mixture of more than one of the choices in equal amount is not the correct answer, because the major product of the reaction is a trans-alkene.
Here is a diagram of the reaction:
H2
/ \
Pt or Pd
/ \
H H
| |
C=C (trans)
| |
H H