Because B-shells are too small, and D-shells are too big.
ME: wearing a wedding dress Compliments
You don't ride horses. Me: Why do you wear sneakers You don't sneak.
BIG-TIME plot hole in my opinion
She outgrew her B shells.
She grew out of her b-shells.
Because she outgrew her B-Shells. Ha...
Because she can't fit into D shells
Because D shells are too big and B shells are too small.