If $0,1,2,\dots,7,8,9$ are coded as $O,P,Q,\dots,V,W,X$, then $45$ will be coded as ______.
$0 → O$
$1 → P$
$2 → Q$
$3 → R$
$4 → S$
$5 → T$
.
So, $45 → ST$
Hence Option B is correct.