The alkyne shown is treated with $\mathrm{H}{}_2$ over Lindlar catalyst. Which structure is the major product?

The compound is hex-3-yne. Lindlar catalyst (Pd on $\mathrm{CaCO}{}_3$, poisoned) delivers two hydrogens to the same face (syn addition) and stops at the alkene, giving (Z)-hex-3-ene. The E isomer arises from Na/$\mathrm{NH}{}_3$ and hexane from complete hydrogenation.