The correct answer is (c). The pH of human blood is 7.4, which is slightly alkaline. A pH of 7 is neutral, a pH below 7 is acidic, and a pH above 7 is alkaline. The pH of blood is important because it helps to regulate the body’s metabolism. If the pH of blood changes too much, it can lead to serious health problems.
Option (a) is incorrect because the pH of human blood is not 3.7. A pH of 3.7 is acidic, and this would not be healthy for the body.
Option (b) is incorrect because the pH of human blood is not 5.9. A pH of 5.9 is also acidic, and this would not be healthy for the body.
Option (d) is incorrect because the pH of human blood is not 11.4. A pH of 11.4 is alkaline, and this would not be healthy for the body.