Remember the Speed/Distance/Time triangle: Speed = Distance over Time,
You can write it in a pyramid like so. Use a finder to cover the one you want to find, so D (distance) is speed multiplied by time. Speed is Distance devided by time.
Always remember to the specific unit and multiply or devide accordingly to minutes, hours, miles or meters!
From here, we can see that 3 times 45 = 135 (Answer D, in Meters).