What is a kinin known for inducing?

Kinin is a type of peptide that is important in the body's response to injury and inflammation. It is primarily known for inducing pain and swelling, which occurs as part of the inflammatory response. Upon tissue injury, kinin release triggers the vasodilation of blood vessels, leading to increased blood flow and the accumulation of fluid in surrounding tissues. This process not only causes swelling but also enhances sensitivity to pain, thus making the area more responsive to potential threats and aiding in the healing process.

The role of kinins in promoting pain and swelling is a significant aspect of understanding how the immune system reacts to tissue damage and infections, which is why option B is the correct answer. Other options, such as muscle contractions or hormonal changes, while also relevant to biological responses, are not specifically tied to the function of kinins in the context of injury or inflammation. Similarly, kinin does not induce infections.