The correct answer is option 4 i.e. the number of people with malarial fever (also contracted from mosquito bites) has increased this yearExplanationOption 4 is the correct answer, as it states both Dengue fever and malarial fever is caused by Mosquito bite; dengue fever had increased because of some other reasons which are not mentioned by the municipal authorities. Since Municipal authorities have concluded that measures to control the mosquito population have failed in this region so as its consequences we can easily say "The number of people with malarial fever (also contracted from mosquito bites) has increased this year"Lets see the given points-Statement (1) negates or contradicts the conclusion of the municipal authorities, as it concluded that measures taken to control the mosquito population had failed; Hence 1st option is incorrect.As there is no data mentioned in the passage related to the reporting of cases and the efficiency of the administrative capabilities; it concludes that the 2nd option is also incorrectStatement 3rd also contradicts the conclusion of the municipal authorities mentioned in the paragraph; hence this option will be incorrect.