surface area of a sphere is 4 times pi timers radius^2
aprox pi=3.14
so surface area=145,000,000
145,000,000=4 times 3.14 times rdaius^2
145,000,000=12.56 times radius^2
divide both sdies by 12.56
11544585.987=r^2
square root both sides
3397.73=radius
round to the hundreds
3397 rounded to the hundreds
3400
the answer is D 3,4000 km