Answer:
I'd say the correct answers are three:
A) it introduced Islam into West Africa for the first time.
B) it demonstrated the tremendous wealth of the Mali empire.
C) it was the first encounter that Europeans had with an African ruler.
Explanation:
Mansa Musa came to power in 1312 and his reign would be marked by an important growth for the region; economic, social and religious, because Mansa Musa was a devout Muslim who promoted this faith in his Empire and spread throughout his territory mosques, madrasas (schools), as well as an important urbanization.
The Empire of Mali was located in what is now northern Guinea and southern Mali. At its height, it had a population of 50 million, made up of a large number of ethnic groups. The strength of the Empire is said to have been due to the decentralization of state administration, and it was also the Empire that reached the largest African territory and retained it the longest.
Mansa Musa was the driving force behind the economic and knowledge boom in the city of Timbuktu. In it, the Sankore University, which exists until today, stands out especially.
As a devout Muslim, his trip to Mecca was an important moment for him. It is precisely this journey that made the name of Mansa Musa cross the Mediterranean and reached the ears of European merchants, historians and builders. The first ones, by the way, extended their commercial routes to Timbuktu, which generated an important exchange with the Empire.
The journey of the Mansa is recorded in the year 1325 and it would take a full year to reach its destination and return to its city. Many things have been written about this trip, because in different oral and written sources, impressive details were recorded that seem to exceed reality.
It is said that during the trip, Mansa Musa built a mosque every Friday and gave generous gifts to the poor of coins and gold dust. By the way, this fact is pointed out as the cause of the devaluation of this metal and an economic destabilization that impacted even a decade later.
Thus, as we can see, this ruler of the Empire of Mali had a great influence on West Africa; his actions and his wealth transcended in such a way that by 1375, in the Catalan Atlas, the Empire of Mali appears represented by the very Mansa Musa holding a gold nugget in his hand as a sign of his wealth. This wealth was not only material, as we can see, but also a deep impulse to the Muslim tradition, of knowledge, architecture and African culture that, some time later, would be disrupted by the fall of the Empire of Mali and the European invasions.