Concept:
This question is based on identifying the item which does not belong to the same category.
Step 1: Check Avast.
Avast is an antivirus software. It is used to protect computers from viruses, malware, spyware and other security threats.
Step 2: Check Quick Heal.
Quick Heal is also an antivirus software. It provides protection against viruses, ransomware, malware and internet threats.
Step 3: Check MacAfee.
MacAfee is also antivirus/security software. It is used for system protection and cyber security.
Step 4: Check Ransom.
Ransom is not antivirus software. It is related to ransomware or ransom demand, which is a type of cyber threat.
Therefore, Avast, Quick Heal and MacAfee belong to antivirus/security software category, while Ransom does not belong to this category.
\[
\therefore \text{Correct Answer is (C)}
\]