Which of the following statements is correct in the context of cyber security?

A. Incident response in cyber security involves identifying and closing vulnerabilities before an attack occurs.

B. CERT-In acts as an early warning system for cyber threats and attacks in India.

C. Tor is an acronym for 'The Onion Router' which is a web browser that enables people to communicate online anonymously to prevent bad guys from tracking their internet activity.

D. Using a virtual personal network (VPN) can help secure a network by encoding data transmitted over it.

Choose the correct answer from the options given below: