Trying to create new task however priority filed has no values!

Trying to create new task however priority filed has no values!

Hello I am trying to create a new work flow, whenever there is a new assignee for a lead, then an automatic task should be option for the new assignee, however whenever I am trying to create this task, i can see that i have to choose the Priority value, and in this field there are no available options to select, how can we solve this?

See the screenshot here:  http://prntscr.com/hhmosj

Thanks.