Refer to the exhibit. Which lines must be added to the script to list the ports that are open?

Question

Options

• Aif result == 0: show "Port {}: Open".format(port) close()
• Bif output == 0: print "Port {}: Open".format(port) open()
• Cif output != 0: print "Port {}: Open".format(port) sock.open()
• Dif result == 0: print "Port {}: Open".format(port) sock.close()

• A
  7% (2)
• B
  3% (1)
• C
  17% (5)
• D
  72% (21)

Explanation

D is correct because Python's socket.connect_ex() returns 0 on a successful connection, meaning the port is open - so if result == 0 is the right condition. print is the valid Python output function, and sock.close() correctly closes the socket object using the proper object-method syntax.

Why the distractors fail:

• A uses show instead of print (not a Python built-in) and close() without the socket object prefix - it should be sock.close().
• B uses the wrong variable name output instead of result (the variable assigned from connect_ex()), and open() is a file operation in Python, not a socket method.
• C also uses the wrong variable output and inverts the condition with != 0 - a non-zero return from connect_ex() means the port is closed or filtered, not open. sock.open() is also not a valid socket method.

Memory tip: Think of connect_ex() like Unix exit codes - 0 means success (port open), anything else means failure. Pair that with the pattern sock.close() (object dot method) to remember you always need the socket variable prefix when closing.

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