Answer: option B and D (1000m/km and minute/60 second) In this question, we have two unit that needed to be converted, kilometer/minutes into meter/second. First, we need to convert km into the meter. One kilometer is equal to 1000 meter. To change kilometer into the meter, the unit used for multiplication should be 1000m/km which is option B. Then we need to convert minute into the second. One minute is equal to 60 seconds. To change "/minute" into "/second" the multiplication unit should be minute/60 second which was option D
