The temperature of Sun’s center is 15 million C and the temperature of outer surface of sun is?

The temperature of Sun’s center is 15 million C and the temperature of outer surface of sun is?

(a) 4000 to 5000 С

(b) 4500 to 5000 C

(c) 5000 to 5500 С

(d) 5500 to 6000 С