Hey everyone. So here we need to convert 6.78 minutes into milliseconds. So we start out with minutes and the first conversion factor is minutes, two seconds. Remember that one minute is equal to 60 seconds minutes cancel out now, we need to go from seconds to milliseconds, so seconds go on the bottom, milliseconds go on top. Since millie is a metric prefix, remember that one milli is 10 to the negative. Three seconds cancel out and we'll have milliseconds at the end. This comes out to be 4.0 68 times 10 to the five milliseconds. And when we do it, in terms of 36 figs, it comes out to 4.7 times 10 to the five milliseconds. So option D would be our final answer.