Find the value of each exponential expressions,

92,83,1°

A 92 = 81,

83

512, 1° = 1

B 92 = 81, 83 = 24, 1° = 0

C

92 = 18, 83 = 24, 1° = 1

D 92 = 18, 83 = 512, 1° = 0