Answer:
B. rain water with a pH of 5.5
Step-by-step explanation:
The substance that is most acidic is rain water with a pH of 5.5. The pH scale ranges from 0-14, with 0 being the most acidic and 14 being the most basic. Therefore, a substance with a lower pH value is more acidic than a substance with a higher pH value. In this case, rain water has a pH of 5.5, which is lower than the pH of bleach (13.0), sea water (8.0), and blood (7.4). This means that rain water is more acidic than these other substances.