Mark the letter A, B, C, or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.

a. It has been found that access to even the most basic green spaces can provide a better quality of life for dementia sufferers and help people avoid obesity.
b. Research also indicates that green roofs can be integrated with drainage systems on the ground, such as street trees, so that the water is managed better, and the built environment is made more sustainable.
c. Besides, there is evidence to demonstrate the social value of green roofs.
d. Ongoing research shows how green roofs in cities can integrate with living walls': environmentally friendly walls which are partially or completely covered with greenery, including a growing medium, such as soil or water.
e. Doctors are increasingly prescribing time spent gardening outdoors for patients dealing with anxiety and depression.