Specificity and progression are things you should work on to improve your physical health. what should the word in italics be replaced with to make this sentence
more precise?
acronytais
principles
muscles
exercises

The correct answer would be option D, Exercises.

Explanation:

Specificity and Progression are Exercises you should work on to improve your physical health.

Specificity is the exercise which targets the specific area of the body to work upon. For example if you try to tone up your belly muscles, it means you are specifying the target area for exercise.

Progression is the increase in the time and intensity of an exercise over a period of time. For example if you do exercise to tone your belly for 5 minutes, then progression is to increase the time from 5 minutes as well as increasing the intensity of the weights you are using.

So specificity and progression are exercises.