The "sensitivity factor" in the model used to represent human environmental impact denotes
a. the sensitivity of governments to carrying capacity demands
b. the sensitivity of endangered species to human population infringementeconomic sensitivity to resource use
c. human sensitivity to what needs to be done to protect the environment
d. the sensitivity of an environment to human pressures

d. the sensitivity of an environment to human pressures

Explanation:

It denotes the environmental vulnerability that is due to the human pressure on the environment.  As the environment is sensitive to the man and has endangered species and sensitivity to resources and thus the carrying capacity of the environment depends on the human activity and thus the fragile environment needs protection. So as the ecological system remains in balance and exists in a harmonious relationship with the man.