Concept:
HTTPS is a secure version of HTTP used for safe communication over the internet.
Step 1: Expand the abbreviation.
\[
{HTTPS} = {Hypertext Transfer Protocol Secure}
\]
Step 2: Evaluate options.
(A) $\times$ incorrect expansion
(B) $\times$ incorrect wording
(C) \checkmark correct
(D) $\times$ incorrect
Hence, the correct answer is Hypertext Transfer Protocol Secure.