Answer:
D
Explanation:
The last one.
The other three are all in proper scientific notation.
The last one does not raise ten to scientific notation. All scientific notation is written with ten as the power after a number between 1 and 9.99999
For example 1.4 * 10^-5 or 1.7*10^16 are both correct written in scientific notation.
The last one is not 10 * 9.4^16 is not correct and is not written in scientific notation.