Roughly, it takes light less than 0.000000003 of a second to travel a one-meter distance. Express this number in the form of a × 10^n where 1 < a < 10 and is a one-digit number.(1 point)

3 × 10^−9
3 × 10^8
3 × 10^−8
3 × 10^9

3 × 10^−9