What is this? Please answer with an explanation

B. Human disturbances

Explanation:

Human disturbances is an example of density independent factor. These human disturbances are actually caused by human activities that are carried out by people. These disturbances result to pollution, destruction of habitats, depletion of resources, urbanization, etc.

Density-independent factors are known to be the factors that influences the birth and death rate of the population. This happens regardless of the population density i.e it does not depend on population.

Some of these density-independent factors  are also food or nutrient limitation, climate extremes, pollutants in the environment, etc.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.