It is one of nature's great ironies that the availability of nitrogen in the soil frequently sets an upper limit on plant growth even though the plants‘ leaves are bathed in a sea of nitrogen gas. The leguminous plants—among them crop plants such as soybeans, peas, alfalfa, and clover—have solved the nitrogen supply problem by entering into a symbiotic relationship with the bacterial genus Rhizobium.
Q. Which of the following situations is most closely analogous to the situation described by the author as one of nature's great ironies?
A That of a farmer whose crops have failed because the normal midseason rains did not materialize and no preparations for irrigation had been made
B That of a long-distance runner who loses a marathon race because of a wrong turn that cost him twenty seconds
C That of shipwrecked sailors at sea in a lifeboat, with one flask of drinking water to share among them
D That of a motorist who runs out of gas a mere five miles from the nearest gas station
E That of travelers who want to reach their destination as fast and as cheaply as possible, but find that cost increases as travel speed increases