The flux philosopher who influenced Plato to explain his world of matter which is constantly changing. His popular expression, "no man steps into the same river twice, " and concluded, change is real, permanence is an illusion.

A. Parmenides
B. Heraclitus
C. Thales
D. Plato

The correct answer is letter B. Heraclitus.

Explanation:

Heraclitus was a Greek philosopher who is well known for believing change is central to the universe. While change is real, permanence is an illusion. No matter how things appear to the senses, they are impermanent, constantly shifting. That explains the metaphor of the river. Because of its constant flow, the water we touch in the river is never the same. Even if we do not perceive any changes, even if we believe it is the same river, its waters are constantly flowing, ever different.

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.