Answer:
B and C are wrong
B: 7.89 x 10^-4
C: 3.15 x 10^2
Step-by-step explanation:
B is not written correctly. The purpose of scientific notation is to get rid of the decimal places with 0s. So instead of 0.789, it should be 7.89 x 10^-4
C is wrong, it should be 3.15 x 10^2
