Answer:
Option (3) "Run the malware in a sandbox and search for a signature in the malware body" is the right answer.
Step-by-step explanation:
Sandboxes are mostly used to run the application which is suspicious and can harm the computer in an environment where this type of application has limited access to the computer files which makes our computer system safe.
As we want to detect the malware, we have to search for the signature in the malware body by running the malware in the sandbox.
Hence according to the scenario, the most appropriate answer is option (3).