Enzymes present in mammals work best at about:

Explanation

Option C is correct. Enzymes in mammals typically work best at around 40°C, closely correlating with their normal body temperature of approximately 37°C. At these temperatures, enzymes achieve optimal catalytic efficiency, allowing them to facilitate biochemical reactions at the highest rates. While enzymes can operate at lower and higher temperatures, their activity diminishes as temperatures deviate from this optimal range. Options A (20°C) and B (30°C) are incorrect because they are below the optimal temperature range, leading to reduced enzyme activity. Option D (50°C) is also incorrect, as many mammalian enzymes would likely denature at this temperature, resulting in loss of function. Therefore, understanding the relationship between temperature and enzyme activity is crucial for answering the question correctly.