Bromide is a better leaving group.
Work Step by Step
1. Identify the possibles leaving groups: - $Tosylate$ ($OTs$) - $Bromide$ ($Br^-$) 2. Determine which one is better. - If we analyze the image on page 218, we will see that, bromide is more stable than tosylate (The group with a sulfur). Therefore, $Br^-$ is a better leaving group.