A Look at the Historical Data Indicates That Velocity for M1

A look at the historical data indicates that velocity for M1

A) has been more variable than the velocity for M2,but both have been fairly constant for the past 65 years.
B) and M2 have both trended downward,but velocity for M2 has been more erratic than velocity for M1₁.
C) has been fairly constant for the past 65 years,but velocity for M2 has trended downward.
D) has trended upward in the past 65 years,but velocity for M2 has been more constant.