D is the only non fragment sentence here, so it must be correct
Answer: D, improving housing and living conditions in cities.
Explanation:
Pilgrimage to Mecca. Mansa Mūsā, either the grandson or the grandnephew of Sundiata, the founder of his dynasty, came to the throne in 1307. In the 17th year of his reign (1324), he set out on his famous pilgrimage to Mecca. It was this pilgrimage that awakened the world to the stupendous wealth of Mali.
the increasing population of humans caused a decrease in the quality of life. Jupiter and Man were mainly responsible for these changes.