The energy source at the center of our galaxy
A)is not visible at optical wavelengths.
B)produces X-rays.
C)must be less than 10 AU in diameter.
D)is not visible at optical wavelengths, produces X-rays, and must be less than 10 AU in diameter.
E)None of the other choices are correct.

Question

Quizplus · Accepted Answer

The statement "is not visible at optical wavelengths" rules out choices A and E. The statement "produces X-rays" narrows it down to choice B or D. However, the statement "must be less than 10 AU in diameter" is only true for choice D. Therefore, the best choice is D - not visible at optical wavelengths, produces X-rays, and must be less than 10 AU in diameter.

The Energy Source at the Center of Our Galaxy