I am using USPS as my only shipping providor, however now  that I have gotten my account from USPS, and set it in nopCommerce, when the customer purchase a product, the customer is presented with some 12 or so different posibilities of USPS shipping options, ( even media) which it would not be applicable.

How could I set it, so my customer only get, say two options:   Priority Mail, and Expess Mail

thank you so much for you assistance