The most reasonable answer i think would be option b: building pedestrian-friendly walkways.
Why? because if they would have to purchase bikes for each household, that would be too expensive.
I think option 3 does not even go in these categories.
And option 4: think not all senior citizens go to the gym. They usually might just walk around the neighborhood once or twice, and go to bed, because their legs hurt.
That is why i think option 2 fits best here.
Hope i helped!
Vegans have difficulty in obtaining adequate amounts of vitamin b 12 in the diet because vitamin b 12 could be found or obtained from meat consumptions and are only less in vegetables. That is why they find it difficult to obtain for they don't consume meat which is where vitamin b 12 could be obtained. Vitamin b 12 is essential in the body for it is important in the brain, as well as the nervous system.
A situation that describes negative leer pressure is doing drugs because it might be cool at the time but it can hurt u bad in the future