One positive example of health fitness advertisements would be advertisements that get you to come to the gym to work out. A negative example would be dieting pills that make it seem like you don't have to put in any work to lose weight healthily.
A negative health and fitness advertisement is such that lie to people with false promises and misleading. A common example of this it's supplements ads, they are design to make people feel and believe that they can achieve physical wellness and a fitness stage by just consuming these products, which is a complete lie. They don't put in the ads that they need proper nutrition and regular exercise to not overload the body with proteins which will transform in fat if they don't move to the gym.
A positive health and fitness advertisement don't mislead, don't abuse people's ignorance. This ads directly or indirectly says to people that magic pills don't exist, wellness and fitness comes with effort and determination. For example, a advertisement that offer a training program that don't directly guarantee weigh loss but motivational and educational advice on how to lose weigh properly.
Answer: Muscular endurance refers to the number of repetitions of a single exercise you can do without needing to stop and rest. So when you are thinking of Muscluar endurance think stamina and in that case, all of them can be correct if that is the most you can do without stopping.
Financially you would struggle because you have to think about your child and pay bills and other finances so that's the biggest challenge and if you don't have any support there's another challenge.