Explanation:
charles darwin proposed thoery of natural selection.he had collected imnumerable specimens of plant and animals.he published concept survival of fittest. while explaining he says that There is always competition for food.only those organism survive which shows adptations in various reasons. it thoery of natural selection.
There are some objections,
1. natural selection is not only factor responsible for evolution.
2. darwin did not mention uesful and useless modifications.
3. There is no explanation about slow and abrupt changes
The answer to this is protein.
Hydrochloric acid in digestive system is found in stomach, which is the only main digestive organ with an acidic pH 2.
In the stomach, only one kind of the primary food substance is chemically digested, which is protein. It is digested with the help of enzyme Pepsin, which breaks protein chains into polypeptides.
After that, the other organs of the digestive system has more of a neutral to slightly alkali condition, which is not related to hcl. Therefore, the answer is protein.
The species that has the same predators as species c would benefit the most