Because the status is an enumeration, which means it’s a collection of constant, static strings. And a Task, can and will normally go trough different of these Statuses, f.e. from “Doing” to “Finished”. So a Task can have many statuses. But each status is, in this model, only given to one Task.
Hence: one-to-many.
I think it should be the other way round, that is a slaStatus is one to many with task. That is because a task can have only one SLA Status, either met the SLA or not. However, one SLA status can be associated with many tasks, e.g. task1 and task2 and task3 have SLA status of “Met SLA” while tasks 4, 5 and 6 have the other SLA status.