Grade A Fancy veggies? What are those?

So I go grocery shopping for some canned vegetables and other groceries, and I see rows and rows of cans labelled Green beans: Grade A, extra fancy. Same for peas, carrots, sauerkraut, even for Rice. What does this mean?

What makes them Grade A? Or fancy? They don’t look too fancy to me! What about Grade B? or C? Can I buy a can of Grade B plain-looking green beans instead?

This is not a complete answer. I could only find the definition of the different grades, no help on “fancy” or where one might find Grade B or Grade C, sorry.

U.S. Grade A Grade A vegetables are carefully selected for color, tenderness, and freedom
from blemishes. They are the most tender, succulent, and flavorful vegetables produced. The
term “fancy” may appear on the label to reflect the Grade A product.

From this site: http://www.ams.usda.gov/howtobuy/canned2.htm