Bitmaps can be combined with regular B+-tree indices for relations where a few attribute values are extremely common, and other values also occur, but much less frequently.

Bitmaps can be combined with regular B+-tree indices for relations whe

1.	Bitmaps can be combined with regular B+-tree indices for relations where a few attribute values are extremely common, and other values also occur, but much less frequently.
A.	Bitmap, B-tree
B.	Bitmap, B+tree
C.	B-tree, Bitmap
D.	B+tree, Bitmap
Answer» B. Bitmap, B+tree