Answer: b) Scalar, scalar, vector.
Explanation: A scalar is just a number, this can be the speed for example, while a vector is a number that also has a direction, for example, velocity.
the speed of a snail: This is just a quantity, this would be a scalar.
the time it takes to run a mile. Just a quantity, this is a scalar.
the free-fall acceleration. The acceleration is the rate of change of the velocity, so this has a magnitude and a direction, so this is a vector.
Then the correct answer is b) Scalar, scalar, vector.
