No Gem, you should have the A's and B's as stated on your plan, sadly you can't exchange them for something else ...
Red/Green - 1 or 2 A's (milk cheese etc), 2B's (bread cereal etc) - If you don't choose to use both A choices, you lose it. You really should use both B choices as they are there for our 'nutritional health'
Easy - 1 A, 1B
If you are doing red/green and only using 1 B choice, perhaps you should look at trying the Easy plan?