Because they can make energy, is free to anybody, and can be found everywhere that you go.
D. Infrared images can show hot spots as red areas.
It is true that r-related species have a short life span and an early reproduction cycle. R-related species also known as r-strategist have a short and simple life span. Due to their simple life span, their nutrient exchange rate with the environment is rapid. Unlike K-selected species, they have the ability to reproduce at a young age. They reproduce a large number of off-springs, but many of their off-springs tend to die before attainment of their reproductive age.