Answer:
Gradually increase the laps the individual swims every couple of weeks
Step-by-step explanation:
Progression principle follows that the intensity of a specific exercise can be increased, or be above the normal range of an individual (which is called overload) over a optimal period of time. In other words, there is an optimal amount of overload you can do, but the increase needs to be done in optimal intervals.
Among all the choices, gradually increasing the individual swims every couple of weeks follows because it is specific to an exercise, and the increase progresses over a couple of weeks. If it is done too suddenly, then this could lead to injury. If it is done too slow, then there will be little to no progress. It cannot also be done randomly, because it can also lead to injury.