A man is running on ground the coefficient of friction between man and ground is $\mu$ . Assume that the center of mass of man moves horizontally Then which statement is incorrect :

• A

  Normal reaction between man and ground is equal to weight of man

• B

  Direction of friction on man is in the direction of motion of man

• C

  Direction of friction on man is opposite to the direction of motion of man

• D

  Maximum acceleration of man can be $\mu$ g