What type of organisms are classified as mesophiles?

Mesophiles are defined as organisms that thrive in temperatures typically ranging from about 20°C to 45°C (68°F to 113°F). These organisms are well-suited for growth in moderate environments, such as those found in human bodies and many terrestrial environments.

The correct choice specifically identifies mesophiles as those parasites or organisms that grow best within this temperature range. This aligns with their classification, as their metabolic processes are optimized for temperatures that are neither too hot nor too cold, allowing them to prosper in environments conducive to their growth and reproduction.

The other options describe different categories of organisms that do not correspond with the characteristics of mesophiles. For example, organisms thriving in extreme heat are categorized as thermophiles, while those flourishing in cold temperatures are known as psychrophiles. Additionally, the description of microorganisms that do not require oxygen relates to anaerobes, rather than the temperature preferences that define mesophiles.