Which geographical formation separates the americas ? separates asia from africa?

This is my last question i can how did religious practices of ancient india influence the modern world? a. christianity and islam began in india and are both major world religions. b. hinduism and buddhism began in india and are both major world religions. c. hinduism began in india and developed into more modern indian religious practices. d. buddhism began in india and developed into more modern indian religious practices.