If the arithmetic mean of the observations $x_1,x_2,x_3,\dots ,x_n$ is $1,$ then the arithmetic mean of $\frac{x_1}{k},\frac{x_2}{k},\frac{x_3}{k},\dots ,\frac{x_n}{k}$ $(k>0),$ is

• A

  greater than l 

• B

  less than l 

• C

  equal to 1

• D

  none of these