Due to which property of an object does it resist any attempt to change its state of motion?

What is inertia?

What does the mass of a body measure?

"The uniform motion is possible when no frictional forces oppose" is the concept of

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

$A$ reference frame attached to the Earth cannot be an inertial frame because