Parker's basketball league added a rule to prevent bias. Which rule MOST likely accomplishes this goal?

Each player must play exactly two quarters each game.
Players need to arrive 15 minutes before every game.
Home teams wear white jerseys; away teams wear dark jerseys.
Coaches must lock up the gym after the last game of the day.

The rule that most likely accomplishes the goal of preventing bias is: "Each player must play exactly two quarters each game." This rule ensures that every player has equal playing time, reducing the potential for favoritism or bias towards certain players.