The correct answer is C: time start daily 3:00 because of how the Cisco NX-OS scheduler syntax is structured. In NX-OS, when defining a scheduler schedule, the correct format to execute a job at a recurring time includes the keyword start, which specifies when the job should begin execution. Cisco documentation for NX-OS scheduler clearly defines that recurring jobs must be configured using the format:
scheduler schedule name < name >
job name < job-name >
time start daily < hh:mm >
The keyword start is mandatory when defining periodic execution. Without it, the command is syntactically incomplete or invalid in NX-OS.
Option A (time daily 3:00) is incorrect because it omits the required start keyword. Options B and D specify weekly execution, not daily, and therefore do not meet the requirement of running the job every day.
Thus, time start daily 3:00 ensures that the backup job runs automatically every day at 3:00 a.m., aligning exactly with the requirement in the question and Cisco NX-OS scheduler configuration standards.