Statement: Many persons in the locality are siagnosed to be suffering from gastro intestinal siseases after consuming poor quality drinking water supplied by the municipal authority. Which of the following substantiates the facts stated in the above statement?

Directions: Below in each question are given two statements (A) and (B). These statements maybe either independent causes or may be effects of independent causes. One of these statements may be the effect of the other statement. Read both the statements and decide which of the following answer choice - correctly depicts the relationship between these two statements .