Mary is worried because dementia is common in her family. she does not want to get that disease. what can she do to decrease her risk? watch fitness videos to learn new technique eat balanced meals without exercise perform at least moderate intensity exercise regularly perform low intensity exercise regularly each week

Explanation:

Dementia is a chronic disease that affects brain's function. The most common condition diagnosed as dementia is Alzheimer. Due to brains affection, dementia is hard to prevent. However, there are several health strategies to decrease the chances of getting dementia:

Among these health strategies, exercising is really important, that will keep the brain active, producing often neurotransmitters, constantly stimulating the body and brain.

Therefore, the answer is third one, because doing a lot of exercise is mandatory.

not really sure sorry just trying to get points