Step-by-Step Comprehensive Detailed Explanation:
* Command Explanation:
* mkdir CompTIA_doc creates the directory, and && ensures the cd CompTIA_doc command executes only if the directory creation is successful.
* Why Other Options are Incorrect:
* A: The & runs commands in the background and does not ensure sequential execution.
* B: + is not a valid operator in shell commands.
* C: || executes the second command only if the first command fails.
* References:
* Linux+ Certification Exam Resources
* man mkdir, man cd