Which scenario breeds the better rider?

[tached1000rr]

Just trying to facilitate some discussion as always:

Okay these are some "generalizations" so use your own frame of reference to guide you. Which scenario below would you say would result in a more skilled rider?

A) Riding a cruiser say 25,000 miles then going to a sportbike?

B) Riding a sportbike for 25,000 miles then going to a cruiser?

And just for extra credit:

C) Riding a harley for 150 miles and going back to a bike