The correct answer is: Option Strict On disallows conversion of String data type to Object implicitly.
Option Strict On is a compiler option that can be used to enforce type safety in Visual Basic. When Option Strict On is enabled, the compiler will generate an error if you try to convert a value of one type to a value of another type without explicitly specifying the conversion.
In the case of converting a String to an Object, the compiler will generate an error because the two types are not compatible. A String is a value type, while an Object is a reference type. This means that a String cannot be assigned to a variable of type Object, and vice versa.
The other options are incorrect because they are all compatible with the String data type. A Double is a numeric type, a Character is a single character, and an Array is a collection of objects. All of these types can be converted to a String without generating an error.
Here is an example of a code that would generate an error if Option Strict On is enabled:
Dim str As String = "Hello, world!"
Dim obj As Object = str
This code will generate an error because the compiler cannot implicitly convert a String to an Object. To fix this error, you can explicitly convert the String to an Object using the CType function:
Dim obj As Object = CType(str, Object)
This code will convert the String to an Object and assign it to the variable obj.
I hope this helps! Let me know if you have any other questions.