question:  Of all the characters, who is seen as an antagonist in the article?
context: SILENCE IS—DEADLY By Bertrand L. Shurtleff Radio is an absolute necessity in modern organization—and particularly in modern naval organization. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] That would be Nelson, his navigating officer. With him came a boatload of scientific apparatus and equipment, including a number of things that looked like oxygen tanks, which were now stored in the forward hold. Androka had watched over his treasures with the jealous care of a mother hen, and spent hours daily in the room in the superstructure that had been assigned as his laboratory. It was Nelson, his shaggy blond brows drawn scowlingly down over his pale eyes; his thin face a mass of tense lines; his big hands fumbling at the neck of his slicker. He was overfriendly with a black-browed bos'n's mate named Joe Bradford—the worst trouble maker on board. Nelson had no answering smile, although there had been a great deal of good-natured joking aboard the Comerford ever since the navy department had sent the scientist on board the cruiser to carry on his experiments. This storm—" Curtis threw his arm around Nelson's dripping shoulders. "But this storm, sir!" Nelson avoided Curtis' friendly eyes and slipped out from under his arm. In a few minutes he returned and handed Nelson a sheet of paper with figures underlined heavily. Nelson's estimate, I'm checking back," he declared, frowning at the two papers and hastily rechecking his own figures. With all these rocks and islets—" "Radio?" repeated the little Czech, thrusting his face between the other two, in his independent fashion that ignored ship's discipline. Then he hastened to the radio room, with Nelson at his heels, and the Czech trotting along behind. For the next two hours, no radio messages can enter or leave my zone of radio silence—of refracted radio waves, set up by my little station on one of the neighboring islets!"
output:  Androka, because his actions severely inconvenienced the crew of the ship.
options:  Androka's assistant because he turned off the radio.  Commander Curtis because he rarely complied with the other crew members.  The radio man on the ship because he could not complete Commander Curtis's orders.  Androka, because his actions severely inconvenienced the crew of the ship.