The correct option is D If the inference is 'probably false' though not 'definitely false' in the light of the facts given.
The passage mentions food grain stock of a particular year and says that the stock of that year is sufficient to withstand two consecutive droughts. This does not imply that the food grain stock would always be in amount that it would last two consecutive droughts. Additionally, we should keep in mind that if the food grain stock of the year is making the news, then it is probably a rare case and not a common occurrence. Therefore D is the best answer.