Answer:
- 120-150 minutes/week.
Explanation:
As per the given description, Ben must practice moderate-intensity cardio-training for at least '120-150 minutes/week' to seek health benefits like 'proper blood circulation, increasing lung capacity, stress reduction, maintaining a healthy weight, enhanced sleep etc. Since Ben has a very busy schedule and thus, he cannot give much time to training but if he desires to seek cardiovascular benefits from the cardio-training he must devote a minimum of 20-30 minutes of training daily that would help him improve his muscle strength, controlled body weight, proper functioning of body, fitness and activeness, etc.