The natural calamity that the passage mentions is ___________.
The correct answer is option A.
It is mentioned in the passage that ‘Water gushed in from all sides and inched up.’ So the natural calamity that the passage mentions is ‘floods’. Thus, option A is the right answer.
Option B is incorrect because heavy rains caused the floods. Heavy rains is not a calamity in itself , it is the cause of the calamity.
Option C is incorrect because ‘electricity failure’ is not mentioned in the passage and it is not a natural calamity.
Option D is incorrect because ‘waterfall’ is not a natural calamity and the question is on the natural calamity being described in the passage.
Hence options B,C and D are incorrect and option A is the correct answer.