In the following passage some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.
In view of last year's H1N1 attack and prevailing .......(1).......weather conditions, the health department officials ......(2)........that the virus will turn more active by January end. In-charge, Integrated Disease ......(3)........Programme (IDSP), Dr Shah, said, "Virus is still active, but not in a major way. In coming months, it is likely to become more active. Last year too, virus had claimed lives in January and February. Therefore, we are ......(4)........as coming months might
.......(5).......a challenge."