Final answer:
Families can best achieve a positive effect on physical health by engaging in activities that promote physical exercise and active lifestyles, such as taking walks together and participating in outdoor play. Therefore, the correct option is A
Step-by-step explanation:
To achieve a positive effect on physical health, families can engage in activities that promote physical exercise and active lifestyles. For example, taking walks together is a great way to spend time together as a family while also getting exercise. Other activities that can be beneficial to physical health include outdoor play, household chores done briskly, and participating in community programs that promote physical activity.