Connecting to an MS SQL Server database with Microsoft's Object Linking and Embedding Database (OLE DB) requires using which of the following providers?

A binary tree:

a. Has a root node. b. Each node has no more than two branches. c. Uses stacks to process the nodes. d. Uses two extra fields for the pointers to the branches. e. All of the above.

3. Suggest data validation checks for data entry screens.

What will be an ideal response?