Answer: The last option.
Step-by-step explanation:
1. By definition a number written in scientific notation has the following form:
Where <em>a</em> is the coefficient (which is a number between 1 and 10 but not including 10) and <em>b</em> is the exponent (It must be an integer).
2. The decimal point of the coefficient must be wrriten after the first digit.
3. Based on this information, the number shown in the last option has the decimal point after the second digit, therefore, it is not written is scientific notation.