The length of a bacterial cell is about 5 x 10 ^−6 m, and the length of an amoeba cell is about 3.5 x 10 ^−4 m. How many times smaller is the bacterial cell than the amoeba cell? Write the final answer in scientific notation with the correct number of significant digits.

1.4 x 10 ^1
7 x 10 ^1
143 x 10 ^1
7 x 10 ^3