In programming languages such as C and C plus plus, which of the following symbols is the scope resolution operator?

Introduction / Context:
The scope resolution operator is a key concept in languages like C and C plus plus, where it is used to qualify names with a particular namespace, class, or global scope. This question asks you to recognize which symbol represents the scope resolution operator, a basic syntax element that appears frequently in object oriented and modular C plus plus code.

Given Data / Assumptions:

• We are considering the syntax of C and C plus plus rather than Java for this specific operator name.
• The question lists several symbol combinations, including a single colon, a double colon, and a colon with a question mark.
• We assume familiarity with common syntax used in class definitions and namespace usage in C plus plus.
• The term scope resolution operator refers to the operator used to state in which scope a name is defined.

Concept / Approach:
In C plus plus, the double colon symbol :: is used as the scope resolution operator. It allows you to refer to global variables when there is a local variable with the same name, to define methods that belong to a specific class, and to access names inside a namespace. The single colon is used in other contexts, such as labels in goto statements or parts of the conditional operator, but not as a scope resolution operator. The combination :? is not a valid operator in standard C or C plus plus.

Step-by-Step Solution:
Step 1: Recall that in C plus plus, a typical method definition outside the class body looks like void MyClass::myMethod() { } where :: connects the class name and the method name.Step 2: When using namespaces, you often write something like std::cout, where :: indicates that cout is a member of the std namespace.Step 3: To access a global variable that is hidden by a local variable, you can use ::varName to refer to the global one explicitly.Step 4: These examples all use the double colon symbol, confirming that it is the scope resolution operator.Step 5: Therefore option B, ::, is the correct choice.

Verification / Alternative check:
If you consult a C plus plus reference or compiler documentation, the operator table lists :: as the scope resolution operator. Writing code with std:cout instead of std::cout results in a compilation error, which shows that the single colon is not correct. Likewise, :? is not recognized as a valid operator by a standard C plus plus compiler.

Why Other Options Are Wrong:
Option A, a single colon, is used in other contexts but not for scope resolution. Option C, :?, is not a standard operator and appears to be an invalid combination. Option D, None, is incorrect because C plus plus clearly defines :: as the scope resolution operator.

Common Pitfalls:
A common beginner error is to mis type namespace usage as std:cout, forgetting the double colon and leading to confusing compile time messages. Another pitfall is forgetting that :: can also refer to the global scope when used alone, which is important when local and global identifiers share names. Becoming comfortable with :: helps you read and write C plus plus code that uses classes, namespaces, and global objects correctly.

Final Answer:
The scope resolution operator in C and C plus plus is the double colon symbol ::.