A. Enough food to eat for all the starving people in the whole world for one year.
B. Research that will take mankind into space and may or may not bring about the development of a new energy source or method of transportation that could potentially save the human race from overpopulation or a supernova.
Which would you choose? Which do you think is more important on the long term? Would you choose differently if the amount of time in item A was different and if the odds of success of item B were different? What's your turning point?