Hello, I would appreciate some help with this question, thank you!

Competing pathways
✅ Desired: SN2 (Williamson ether)
Nucleophile:Electrophil,allylic secondary bromide ,Product, allylic ether
Allylic halides are much more reactive toward substitution because the transition state is stabilized (and SN1/SN2 paths are both facilitated). So you can still get a good amount of Williamson ether.
Yes, elimination is possible because it's 2° halide, but allylic activation makes substitution competitive/likely, so the Williamson ether product is still a reasonable intended answer. In a real lab, you might get a mixture (ether + conjugated diene), and you'd optimize solvent/temperature to favor SN2.