Which of the following describes a quantity that has both magnitude and direction?

The concept at the core of this question is understanding the difference between scalar quantities and vector quantities. A vector is defined as a quantity that possesses both magnitude and direction. This is essential in various fields such as physics and engineering because it allows for a complete description of physical phenomena that are influenced by both how much (magnitude) and in which way (direction) forces or movements occur.

For example, when discussing motion or forces, stating that an object is moving at a speed of 10 meters per second to the north encompasses both the amount of motion (10 m/s) and its direction (north), which is characteristic of vector quantities.

In contrast, scalar quantities, such as temperature or mass, only describe magnitude without any directional component. While resultant pertains to the combination of two or more vectors, and force can be a specific type of vector quantity often discussed in physical scenarios, it is the term "vector" that universally encapsulates anything defined by both magnitude and direction across various applications. Thus, the most accurate answer that fully encompasses this definition is vector.