Arjun Mehta, a red team specialist at Sentinel Dynamics, is conducting a controlled reconnaissance assessment...

The correct answer is B. IP Address Decoy.

The scenario describes scan activity appearing to originate from several different systems so that the real tester’s host is hidden among other apparent sources. This is the purpose of IP Address Decoy scanning.

CEH-aligned reconnaissance and evasion material explains that IP Address Decoy hides the real source of a scan among multiple decoy source addresses, making it appear that both the decoys and the real host are scanning the target. It also gives the Nmap example nmap -D RND:10 X.X.X.X, which generates decoys and randomly places the real source IP among them .

Option A. Source Routing is incorrect because source routing attempts to specify the path a packet takes through the network.

Option C. Source Port Manipulation is incorrect because changing the source port does not create multiple apparent originating systems.

Option D. IP Address Spoofing is incorrect because simple spoofing replaces the source address and can prevent responses from returning to the attacker. Decoy scanning specifically mixes the real source with multiple decoys.

Therefore, the best answer is B. IP Address Decoy.