Answer: b. has a backward-bending portion.
Explanation:
A backward-bending supply curve shows what happens when people substitute higher wages for more leisure time like Amari is doing in this scenario.
At a higher wage, people will be able to work for shorter hours as such a job will still give them the same amount of money as working longer in lower paying jobs.
After they get a certain level of payment from the higher paying job, they will then substitute the remaining hours for leisure. This creates a backward-bending curve because labor hours are reducing past a certain level of wages.