The answer to the question is sound
Betelgeuse is one of the largest known stars and is probably at least the size of the orbits of Mars or Jupiter around the sun. That's a diameter about 700 times the size of the Sun or 600 million miles. For a star it has a rather low surface temperature (6000 F compared to the Sun's 10,000 F).
Answer:
80%
Explanation:

800 / 1000 = 0.8
Efficiency = 0.8 *100 = 80%