What is the difference between a vector and a scalar?

a
A vector is only used in measuring forces, a scalar is only used in measuring mass
b
A vector measurement is required for distance, a scalar measurement is required for displacement
c
A vector is only measured in SI units, where scalars are only measured in US Customary units
d
A vector measurement contains a direction and magnitude, a scalar measurement only contains a magnitude

d) A vector measurement contains a direction and magnitude, while a scalar measurement only contains a magnitude.