What practice does the Qu'ran allow that many other religions prohibit?

The correct answer is polygamy.

Explanation:

According to Islamic law, men can have up to four wives at one time.

Polygamy, or the practice of being married to multiple wives, is one of the practices that Qur'an allows and other religions prohibit.

Its main purpose was to provide care to all widows and orphans in a society in which women did not have any rights to be independent or to earn some money. Qur'an allows polygamy if all wives are treated justly.

This practice is neither mandatory but merely permitted, although it is strictly forbidden in another religion, for example, Christianity, Hinduism, etc.