$Assertion$ : The driver in a vehicle moving with a constant speed on a straight road is in a non-inertial frame of reference.
$Reason$ : $A$ reference frame in which Newton's laws of motion are applicable is non-inertial.

• A
  If both $Assertion$ and $Reason$ are correct and the $Reason$ is a correct explanation of the $Assertion$.
• B
  If both $Assertion$ and $Reason$ are correct but $Reason$ is not a correct explanation of the $Assertion$.
• C
  If the $Assertion$ is correct but $Reason$ is incorrect.
• D
  If both the $Assertion$ and $Reason$ are incorrect.