To enable Strict Type Checking in VB.NET, you need to use the "Option Strict On" keyword. This will enforce data type checking for all variables, parameters, and return types in your code.

Option Explicit, on the other hand, enforces explicit declaration of all variables in your code.

Option Strict Off disables strict type checking and allows automatic type conversions, making it easier to write code but potentially less safe.

Therefore, the correct answer is:

The Answer is: A. With OPTION STRICT ON keyword