question:  Why does the Brain select Jery to hold the amnesty?
context: MASTER SPY OF THE RED PLANET Jery Delvin had a most unusual talent. So when the Chief of World Security told him that he had been selected as the answer to the Solar System's greatest mystery, Jery assumed that it was because of his mental agility. But when he got to Mars to find out why fifteen boys had vanished from a spaceship in mid-space, he found out that even his quick mind needed time to pierce the maze of out-of-this-world double-dealing. For Jery had become a walking bomb, and when he set himself off, it would be the end of the whole puzzle of THE SECRET MARTIANS—with Jery as the first to go! After sixteen years of education, Jack found himself teaching high school English in Chicago, a worthwhile career, but "not what one would call zesty." He says, "I'd like to say I do this for fulfillment, or for cash, or because it's my destiny; however, the real reason (same as that expressed by Jean Kerr) is that this kind of stay-at-home self-employment lets me sleep late in the morning." "Jery Delvin?" said the one on my left, a note of no-funny-business in his brusque baritone. Yes," I said, some terrified portion of my mind waiting masochistically for them to draw their collapsers and reduce me to a heap of hot protons. Security men were not hired for their loquaciousness. Because the speaker was Philip Baxter, Chief of Interplanetary Security, second only to the World President in power, and not even that in matters of security. "Jery Delvin," he read, musingly and dispassionately. Honest, sober, civic-minded, slightly antisocial...." But if I spot it in less, they throw it out and start over again. "You were chosen, from all the inhabitants of this planet, and all the inhabitants of the Earth Colonies, by the Brain."
output:  Because of his ability to parse situations.
options:  To prevent someone like Baxter wielding and misusing it.  Because he's not really qualified, making him a wildcard.  Because of his ability to parse situations.  Because he will responsibly wield the amnesty.