Proper Attire, a company that rents uniforms to major corporations, requires its new delivery drivers to go through a year$-$long training regimen before they receive their own delivery routes. First, new drivers go through three months of training to learn the whole scope of the business before setting foot in a delivery truck. Then they ride with experienced delivery drivers for nine months to watch how they interact with customers. According to the service marketing triangle, their training program is a form of $\_\_\_\_\_$ marketing $($enabling the promise$)$

Multiple Choice

Integrated

Interactive

Internal

Hierarchical

External