Which unit defines flux density?

Flux density is defined as the strength of a magnetic field per unit area, which is commonly described in terms of the unit "gauss." The gauss is a cgs (centimeter-gram-second) unit of measurement that specifically quantifies magnetic flux density. One gauss is equal to one maxwell per square centimeter. This makes it the appropriate unit for measuring the magnetic field density in various applications, particularly in electromagnetism and magnetics.

Other options represent different physical concepts. For instance, the maxwell measures magnetic flux rather than flux density. An ohm is the unit of electrical resistance, and a mho (the inverse of ohm) is a unit of electrical conductance. None of these concepts directly relates to measuring magnetic flux density. Therefore, the gauss is clearly the correct answer for defining flux density.