What does a vector quantity have?

A vector quantity is defined by both its magnitude and direction, making it distinct from scalar quantities, which have only magnitude. In this context, magnitude refers to the numerical value or size of the quantity, while direction indicates where the vector points in space. Additionally, vector quantities also include the necessary units that denote the measurement of the vector, such as meters for displacement or newtons for force.

The correct choice highlights the essential components of a vector: it must not only possess a size (magnitude) but also specify a direction, and it must be paired with appropriate units to provide a complete understanding of the quantity being described. This framework allows for accurate representation and analysis in fields like physics and engineering, where directional data is crucial for understanding forces, velocities, and other vector-based phenomena.