The correct answer is: Option On.
Option On ensures every variable and named constant is declared with a data type. This is important because it helps to prevent errors and makes the code more readable. When a variable is declared with a data type, the compiler can check to make sure that the variable is being used in a way that is consistent with its data type. This can help to prevent errors such as trying to assign a value of one data type to a variable of another data type.
Option Infer Off does not require variables and named constants to be declared with a data type. This can make the code more concise, but it can also make it more difficult to read and debug. When a variable is not declared with a data type, the compiler will infer the data type from the context in which the variable is used. This can be helpful in some cases, but it can also lead to errors if the compiler makes an incorrect inference.
Option On is the preferred option for most code. It helps to prevent errors and makes the code more readable. Option Infer Off can be used in some cases, but it is important to be aware of the potential risks.