What religion is not only practice today but also served as the foundation for both christianity and islam

Judaism

Explanation:

Some people consider Christianity, Islam, and Judaism “Abrahamic religions” because of the role Abraham played in each. Abraham was the founder of the Jewish religion, which later led to the creation of Christianity and Islam.

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.

the answer to your question is,

d. when a child was born.

-mabel < 3