They want to show people of the younger gen about nature, trees, animals and etc in nature.
I think it’s d but I might be wrong
<span>The Classical Period or Golden Age of Greece, from around 500 to 300 BC, has given us the great monuments, art, philosophy, architecture, and literature which are the building blocks of our own civilization. The two most well-known city-states during this period were the rivals: Athens and Sparta.
Hope this helps</span>
<span>Assuming that this is referring to the same list of options that was posted before with this question, the best option is "exercise" since it can clear the mind. </span>