Which of the following is the successor of SSL?

Which of the following is the successor of SSL?
A . GRE
B. RSA
C. IPSec
D. TLS

Answer: D

Explanation:

TLS

https://en.wikipedia.org/wiki/Transport_Layer_Security#History_and_development

TLS 1. 0 was first defined in RFC 2246 in January 1999 as an upgrade of SSL Version 3.0, and written by Christopher Allen and Tim Dierks of Consensus Development. As stated in the RFC, "the differences between this protocol and SSL 3.0 are not dramatic, but they are significant enough to preclude interoperability between TLS 1. 0 and SSL 3.0". Tim Dierks later wrote that these changes, and the renaming from "SSL" to "TLS", were a face-saving gesture to Microsoft, "so it wouldn’t look [like] the IETF was just rubberstamping Netscape’s protocol".