The Sun's mass is 19.89 × 1029 kg. Which of the following is the best estimate of the Sun's lifespan?
A.
500 million years, or 0.5 billion years
B.
1,000,000 million years, or 1 trillion years
C.
10,000 million years, or 10 billion years
D.
100,000 million years, or 100 billion years