Determine the topic of the question-answer pair. Question: "what is the singer Stevie Wonders full name?"; Answer: "Stevland Hardaway Morris (born May 13, 1950 as Stevland Hardaway Judkins), known by his stage name Stevie Wonder, is an American singer, songwriter, and multi-instrumentalist, a child prodigy who developed into one of the most creative musical figures of the late 20th century."? Topic:
Ans: Stevie wonder

Determine the topic of the question-answer pair. Question: "what is cta used for?"; Answer: "Computed tomography angiography (CTA) is a computed tomography technique used to visualize arterial and venous vessels throughout the body."? Topic:
Ans: Computed tomography angiography

Determine the topic of the question-answer pair. Question: "what caused the world war 2?"; Answer: "The culmination of events that led to the outbreak of war are generally understood to be the 1939 invasion of Poland by Germany and Soviet Russia and the 1937 invasion of the Republic of China by the Empire of Japan ."? Topic:
Ans: Causes of World War II

Determine the topic of the question-answer pair. Question: "how many presidents have been assassinated?"; Answer: "Four sitting presidents have been killed: Abraham Lincoln (the 16th President), James A. Garfield (the 20th President), William McKinley (the 25th President) and John F. Kennedy (the 35th President)."? Topic:
Ans: List of United States presidential assassination attempts and plots