Flood waters can be channeled to provide irrigation is true about the development of farming in Summer. The correct option among all the options that are given in the question is the last option or option "D". Without adequate amount of water, it is not possible to farm in the summer months.
After reviewing the graph you posted with the question and also reviewing the 2011 reference tables, the estimated number of daylight hours that can occur on January 1 at 40° N latitude is 8.5 hours - 9.5 hours. Either of these will be correct to use.
All 3 sciences, geology, criminology and psychology in human geography, oceanography (if thats a thing), vulcanology