Highly intelligent joke

The joke I liked:
Sonia Gandhi met the Queen of England in her palace

Sonia: “Your Majesty, any tips you can give me to stay in power, the way you have been for so long?”

“Well,” said the Queen, “the most important thing is to surround yourself with intelligent people.”

Sonia frowned, and then asked, “But how do I know the people around me
are intelligent?”

The Queen: “Easy; you just ask them to answer an intelligent riddle.”

The Queen pushed a button on her intercom. “David Cameron, would you come in here, please?”

David Cameron walked into the room and said, “Yes, ma’am?”

The Queen smiled and said, “Answer me this please, David. Your mother and father have a child. It’s not your brother and it’s not your sister. Who is it?”

Without pausing for a moment, David Cameron answered, “That would be me, ma’am.”

“Very good! Thank you, David !” said the Queen.

Then she turned to Sonia with a smile and said “See?”

Now its Sonia’s turn to apply the same logic….

Sonia went back to India and asked Rahul..
“Rahul , answer this for me. Your mother and your father have a child. It’s not your brother and it’s not your sister. Who is it?”

“I’m not sure,” said Rahul Gandhi . “Let me get back to you on that one…”

Rahul Gandhi went to his advisors and asked every one, but none could give him an answer…

Finally, he ran into Narendra Modi and asked, “Narendrabhai, can you answer this for me? Your mother and father have a child and it’s not your brother or your sister. Who is it?”..

Narendra Modi answered, “That’s easy, it’s me!”..

Rahul Gandhi said, “Thanks!”

Then he went back to Sonia. “I did some thinking and I have the answer to that riddle. It’s Narendra Modi…”?

Sonia slapped him….
and shouted..
“No ! You dumb idiot! It’s David Cameron