If an american lives in a city with no parks, this obstacle to exercise is considered

environmental barrier

Environmental barriers to physical activity is a lack of resource. Parks provide an option for the people to do physical activities with minimal or no equipment or facilities, that doesn’t cost anything and is convenient. Lack of parks will pose a barrier to physical activities such as walking, jogging, dancing, rope skipping etc.

Poor Location

Explanation: Because a environmental barrier, can cause issues with motivation to continue exercise.

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.