Which sentence from the passage would you quote to show the exact moment that the author came up with the idea of circling the globe in less than 80 days? a) "it is easy to see how one thought followed another." b) "it is sometimes difficult to tell exactly what gives birth to an idea." c) "'and why not? ' the thought came: 'i need a vacation; why not take a trip around the world? '" d) "i had spent a greater part of the day and half the night vainly trying to fasten on some idea for a newspaper article."