What will be the major product of following sequence of reactions?

The starting material is a terminal alkyne: n-Bu-C≡CH.

• Reaction with n-BuLi: strong organolithium base deprotonates the terminal acetylenic proton to form a nucleophilic carbanion:
  n-Bu-C≡C- Li+

• 
  
• Reaction with n-C5H11Cl: The carbanion performs an SN2 nucleophilic substitution on the primary alkyl halide, extending the chain into an internal alkyne:
• n-Bu-C≡C-C5H11
  

Step 2: Stereoselective Reduction

The internal alkyne is treated with Lindlar's Catalyst (Pd/CaCO3 poisoned with quinoline) and H2.

• Lindlar's catalyst is a heterogeneous, deactivated catalyst that reduces alkynes selectively into alkenes without reducing them all the way to alkanes.
• The mechanism occurs via syn-addition (both hydrogen atoms deliver to the same face of the triple bond simultaneously).
• This stereospecific addition yields exclusively a cis-alkene (Z-alkene) geometry.