Aconstitutional monarchy provides what power to a monarch?

Most constitutional monarchies employ a parliamentary system in which the Monarch may have strictly Ceremonial duties or may have Reserve Powers, depending on the constitution. They have a directly or indirectly elected prime minister who is the head of government, and exercises effective political power.

Constitutional Monarch has "Unlimited Power". He/she can elect anyone for anything, can make a change in constitution etc. & that power transmits from him to his Children. 

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Ithink is public relations

The answer would be a (carbohydrates)