It's A. Temperature changes modify the enzyme shape, so they no longer fits.
Hippos likely evolved from a group of anthracotheres about 15 million years ago, the first whales evolved over 50 million years ago, and the ancestor of both these groups was terrestrial. These first whales, such as Pakicetus, were typical land animals. They had long skulls and large carnivorous teeth. Hope I’ve helped ;)
Answer:
For example, addition of an orange chromic acid reagent to some compounds causes the chromium reagent to change to a blue-green color (Figure 6.37a). This is considered a "positive" test result, and in this case indicates the presence of a functional group that can be oxidized (alcohol or aldehyde).
