The correct answer is D) The purpose of the harem arrangement was to ensure that there was a strong heir to the throne.
What kept real Turkish harems from being simply pleasure palaces, as they are generally portrayed by Hollywood was that "The purpose of the harem arrangement was to ensure that there was a strong heir to the throne."
Turkish, "harem" can be translated into English as "wife." It was a sacred place in any house during the Ottoman years in which the man of the house -the ruler- had his many wives not just for pleasure purposes, but mainly because for men, their heir was an important part of the Turkish life. No foreigner was allowed to enter the Turkish harem. It was so private and intimate place just for the family.