The correct option is B 70 percent of the total water available in the country is polluted
NEERI has reported that 70% of the total water available in the country is polluted. Refer to the lines: According to the National Environment Engineering and Research Institute (NEERI), a staggering 70 percent of water available in the country is polluted.
Option B is the right choice.
Option A is rejected as it is only partially correct. NEERI did not say that the situation is irreversible.
Options C and D are ruled out as these statements cannot be ascribed to NEERI. Remember, even though these facts are there in the passage, these do not answer the question asked in the passage.