Why is a magnetic field a vector quantity?
a.
directional force
b.
directional speed
c.
specified location
d.
it produces long field lines.
e.
it produces field lines that are close together.

A magnetic field  is a vector quantity because of directional force.

Option A

Explanation:

The magnetic field at any case is a vector quantity as it has both magnitude and direction. A magnetic field has a direction associated with a field as well as the strength of the field. The magnetic field is the space that the magnet creates around itself and is hence a vector quantity as it can be experienced. The S.I. unit of magnetic field is Tesla. It is to be noted that a magnetic field always contains strength.

come closer and become far apart and become steam/gas