Increasing the original price of an article by 10 percent and then increasing the new price by 10 percent is equivalent to increasing the original price by  Choose the correct choice from the following: A) 20 % B) 20.5 % C) 20.8 % D) 21 % E) 21.8 %

Rationale: "1.1 * 1.1 * x = 1.21 * x the answer is d ."
Answer: D