Which of the following is a density-dependent factor?

fire

water

temperature

hurricane

Density-dependent limiting factors include:•   competition•   predation•   parasitism•   disease
Density-dependent factors operate only when the population density reaches a certain level. These factors operate most strongly when a population is large and dense. So the answer is B water the more animals the less water there is available.

An autotrophic protist - they can perform photosynthesis and mainly consist of unicellular algae. they can be divided into number of systematic group according to the shape of their cell and the type of photosynthetic pigments they use.