Question

what contributed to the spread of religious beliefs across ancient civilizations?
policies that isolated civilizations from one another
trade routes that limited interaction between different cultures
policies that encouraged the use of one religion across all cultures
trade routes that spread different beliefs across regions

Explanation:

Trade routes facilitated cultural - including religious - exchanges. Isolationist policies and limited - interaction trade routes would hinder the spread of religious beliefs. Policies promoting one religion across all cultures is not a common factor in the spread across different ancient civilizations. Trade routes spreading different beliefs across regions contributed to the spread of religious beliefs.

Answer:

Trade routes that spread different beliefs across regions