Unscientific poll of 179 people who answer questions like this for $.05 each on Amazon Mechanical Turk, probably about half of whom are in India:
Obama: 179/179 (Obama/President Obama/Barack Obama)
Queen Elizabeth: 174/179 (Elizabeth/The Queen/Queen Elizabeth/Queen Elizabeth II)
I accepted various misspellings of Barack and Elizabeth and even "Kwan."
Wrong answers: Victoria, Margaret Thatcher, Ms Bush, Elizabeth Taylor,Jone Johnson Lewis