Step 1: Recall the types of secretarial duties:
The duties of a private secretary are grouped as routine duties, discretionary duties and confidential duties.
Step 2: Understand discretionary duties:
These are duties where the secretary uses own judgement and acts without waiting for orders.
The secretary takes the initiative in such work.
Step 3: Match the example:
Briefing the executive about the day's work, important mail or pending matters is done on the secretary's own initiative.
So it is a discretionary duty.
Routine duties are fixed daily tasks, such as handling mail and phone calls. Confidential duties deal with secret papers. Neither fits the blank.
Final Answer:
The missing word is discretionary.