C. Not all techniques work well for all people in all situations.
If we look back in history, there have been some famous people who offered their techniques on time management.
Benjamin Franklin, for instance, rigorously kept a log of all his daily activities.
Letts of London is a famous maker of calendars and appointment books -- which was begun by John Letts way back in 1796, when he founded a stationery company, and in the early 1800s was the first to introduce a commercial diary / appointment book for merchants.
President Dwight Eisenhower had a system for managing time and tasks. He classified items according to their urgency and importance. Urgent and important items were dealt with immediately. Urgent but unimportant items were assigned to staff members to handle. Important, but not urgent, items were scheduled onto a calendar for handling at an appropriate time. Items that were neither urgent nor important were to be reduced or eliminated from his schedule.