Which of these is a description of the relation?
reaction velocity decreases with an increase in temperature.
reaction velocity always increases with increase in temperature,
reaction velocity remains constant with an increase in temperature.
reaction velocity increases up to a certain temperature before decreasing,
d)

The correct description of the relation is reaction velocity always increases with an increase in temperature (option B).

Explanation:

A chemical reaction can be affected by a variety of factors, including the concentration of reactants, pressure and temperature. In the case of temperature, the reaction rate increases depending on the temperature increase.

In a chemical reaction, a temperature -or heat - elevation results in an increase in the speed of motion of each component's particles, while increasing energy and effective shock between them.

Reaction → heat →  increased energy → greater effective shocks of particles.

As a result of this, the relationship between reaction velocity and temperature is that at a higher temperature makes a reaction faster.

Learn more:

Chemical reactions and temperature link