Should some radion button of a "shipping method" be pre-selected on "checkout" page?

I have a checkout page and a list of radio buttons for a shipping method. While the opinions vary whether or not some value should be pre-selected wherenever there's a radio button list, my case is a little different because a user has to select an option to proceed.

Should I pre-select the 1st, cheapest and slowest, shipping option?