The best answer is C. Execute the file in a sandbox.
Antivirus alone may miss new, obfuscated, or modified malware, including ransomware. A sandbox provides an isolated environment where the file can be safely executed and observed for malicious behavior such as:
file encryption activity
process spawning
registry changes
network callbacks
persistence attempts
Why the other options are incorrect:
A). Review the file in a code editor.Many malicious files are compiled, packed, or obfuscated, so this is not a reliable analysis method.
B). Monitor the file connections with netstat -ano.This only shows network connections and would not fully reveal ransomware behavior.
D). Retrieve the file hash and check with OSINT.This helps only if the malware is already known. New variants may not match existing threat intelligence.
From a SY0-701 perspective, dynamic analysis in a sandbox is the strongest step for safely identifying malicious file behavior.