Which one below in relation to the concept of materiality is not correct?

Select one:

a.

An amount that is equal to or greater than 10% of the appropriate base amount is presumed to be material.

b.

The higher the risk, the higher the materiality an auditor uses.

c.

An amount that is equal to or less than 5% of the appropriate base amount is presumed not to be material.

d.

whether an amount between 5% and 10% is material is a matter of judgment.