Comprehensive and Detailed Explanation From Exact Extract:

The question is incomplete, as the definition of the Greeting() function is not provided. However, based on standard programming problem patterns and the output options, we assume Greeting() is a function that outputs "Hello!" each time it is called. According to foundational programming principles, calling a function multiple times repeats its output unless state changes occur.

Assumption: Greeting() outputs "Hello!" to the console (e.g., in Python: def Greeting(): print("Hello!")).

Calling Greeting() twice outputs "Hello!" twice, concatenated in the output stream as "Hello!Hello!" (assuming no extra newlines or spaces, as is typical in such problems).

Option A: "Hello!." This is incorrect. A single "Hello!" would result from one call, not two.

Option B: "Hello!!." This is incorrect. This suggests a modified output (e.g., adding an extra !), which is not implied by the function’s behavior.

Option C: "Hello!Hello!." This is correct. Two calls to Greeting() produce "Hello!" twice, appearing as "Hello!Hello!" in the output.

Certiport Scripting and Programming Foundations Study Guide (Section on Function Calls and Output).

Python Documentation: “Print Function” (https://docs.python.org/3/library/functions.html#print).

W3Schools: “C Output” (https://www.w3schools.com/c/c_output.php).