If sufficient rest is taken between workout activities targeting specific muscle groups, how many sessions of the same activity can safely be performed in a one-week period at the most?

The correct answer should be 4 sessions per week. There should always be a break day where you rest to regain strength to keep on practicing. Lower leagues for children for basketball for example commonly have 3-4 pracice sessions per week, and a game on the weekends, which fits the plan of working and resting.