An example of a density-independent factor would be
a) blight (a mold disease) in a wheat field
b) record cold temperatures that kill subtropical plants in northern florida
c) suitable nest sites for a flock of kirtland's warblers
d) wolves that prey on elk in yellowstone national park
e) a specialist searching for the one species of plant that is its food

(B) record cold temperatures that kill subtropical plants in northern Florida

Explanation:

This is any influence that has a negative impacts on a population’s fertility or mortality rate irrespective of the population density.

Examples of density dependent factors are physical factors of the environments, temperature, pollution,natural disasters, and atmospherics oxygen levels

i thinking chemical change