A = CF, B = 2B, C = 3B, but...
Is "B" young and does he still have some defensive upside? I had a stud prospect whom I steered away from shortstop because his AA would never be better than 81. He played 2B/3B for his first 5 ML seasons and was an all-star and gold glove 2B in his 4th and 5th seasons. Last season, with an opening at SS and having signed him to a $9.9milx5 contract, I moved him to short with defense of 79/82/91/79. After starting off with 5 errors in his first 10 games, finishing with 25 in 133 SS starts didn't look bad. His +/- was a push at 2/2 and, with a 77 range 90 glove 2B in most games, we led the world in double plays.
I'm wishing I'd made that move a couple of seasons earlier because my player is now 26. He improved to 83 glove in the offseason but is running out of "improvement time".
So, if your current shortstop has 80+ range, you might think of moving him to CF, putting A at 2B, B at SS, C at 3B. You'll get a few more errors at SS, but you'll have a great arm in CF and you'll get a ton of double plays if your pitchers are decent with groundballs. And you have a gold glove at 3B any way you do it.