Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
diplomat—but on Groac it sure helps! compliments, et cetera, to the Ministry of Culture of the Groacian Groaci wish only friendship with the Terrestrials, but—" reaching for the safe-lock release.... "Don't!" Retief jumped—too late. The door burst inward. A crowd of crested Groaci pressed into the room, "You can't offend the Groaci," Miss Meuhl said sharply. "Consul Whaffle of armed Groaci in the consulate?" "I wrote them for you. They're just as Consul Whaffle would have wanted them." "Did you write all Whaffle's letters for him, Miss Meuhl?" you do. Don't add violation of the Consulate to the list of Groacian Groaci. I certainly hope you're not thinking of openly intruding—" "The Groaci are a very sensitive race. They don't welcome outworlders "Certainly not on Groac." you close the office." Miss Meuhl's face was set in lines of grim disapproval as he closed the door. The pale-featured Groacian vibrated his throat-bladder in a distressed bleat. "The specific instructions of the Archivist." The Groacian's voice rose direction of the Terrestrial Consulate General. The few Groacians on the street eyed him furtively, veered to avoid him as he passed. Flimsy high-wheeled ground cars puffed silently along the resilient pavement. The air was clean and cool. At the office, Miss Meuhl would be waiting with another list of complaints. Retief studied the carving over the open doorways along the street. Groacian equivalent of a bar. Retief went in. A Groacian bartender was dispensing clay pots of alcoholic drink from "To not enjoy my poor offerings," the Groacian mumbled. "A pain in the digestive sacs "To be grappled in by peace-keepers for poisoning of—foreigners." The barkeep looked around for support, found none. The Groaci customers, eyes elsewhere, were drifting away. "The procuring of a cage," a thin voice called from the sidelines. "The displaying of a freak." Retief turned. A tall Groacian vibrated his mandibles in a gesture creature was drunk. "To choke in your upper sac," the bartender hissed, extending his eyes toward the drunk. "To keep silent, litter-mate of drones." door. The other Groaci released him, hurried back inside. Retief looked at the weaving alien. "To begone, freak," the Groacian whispered. "To be pals," Retief said. "To be kind to dumb animals." "To not endure such insolence!" The Groacian advanced toward Retief. The Groacian reached for him, missed. A passer-by stepped around him, Groacian. Retief stepped around him, seized his collar and yanked. The Groacian are two gentlemen waiting to see you. Groacian gentlemen." you." "I'm sure you don't. Come along. And bring an official recorder." Two Groaci wearing heavy eye-shields and elaborate crest ornaments indicative of rank rose as Retief entered the room. Neither offered a courteous snap of the mandibles, Retief noted. They were mad, all right. Consul," the taller Groacian said, in lisping Terran. "May I present "One hour ago," The Groacian said, "a Groacian national was brought "Really!" Miss Meuhl exclaimed, rising. "I wash my hands—" "Just keep that recorder going," Retief snapped. "I'll not be a party—" hands—" "Hogwash," Retief said. "That tune went over with my predecessors, but it hits a sour note with me." answers, and stayed on to dig around a little. After a week they left. Somewhat annoying to the Groaci, maybe—at the most. If they were innocent." "IF!" Miss Meuhl burst out. your—" "Save the protests, Fith. You have some explaining to do. And I don't think your story will be good enough." diplomatic mission." diplomatic circle "Enough!" Fith's mandibles quivered in distress. "I can talk no more of this matter—" "You'll talk to me, or there'll be a task force here in five days to do they were exhibited to the gentle Groaci public. Hauled through the communicate with each other. Altogether it was a very amusing exhibit. Fith made a choked noise and spoke rapidly to Shluh in Groacian. Shluh retracted his eyes, shrank down in his chair. Miss Meuhl opened her mouth, closed it and blinked rapidly. narco-interrogation would get that out of any Groacian who saw the brisk time of it hiding the ship, and shutting everybody up. A close call, eh?" friendship. We invited the opening of diplomatic relations. We made The two Groacians exchanged looks. A Groacian threw a switch. A weak bluish glow sprang up. "How did you shield it so the detectors didn't pick it up?" panels, the litter of sheared bolts, scraps of wire and paper. A thin frosting of rust dulled the exposed metal where cutting torches had sliced away heavy shielding. There was a faint odor of stale bedding. Silently, the Groacians led the way back out through the tunnel and she, Fith? I won't settle for a hundred-ton lifeboat." Fith erected his eye stalks so violently that one eye-shield fell off. "I know nothing of ... of...." He stopped. His throat vibrated rapidly Retief eyed Fith. "Don't try it," he said. "You'll just get yourself in deeper." Fith clacked his mandibles angrily, eye stalks canted aggressively toward the Terrestrial. "Out of deference to your diplomatic status, Terrestrial, I shall cultural aspects of life at Groac. Especially, I should not venture out the Groacian government." In the front seat, Shluh looked straight ahead. The loosely-sprung vehicle bobbed and swayed along the narrow highway. Retief listened to the rhythmic puffing of the motor and said nothing. III going to tell you. I have to move rapidly now, to catch the Groaci off Meuhl snorted. "I really can hardly blame the Groaci. They are not a sophisticated race "The Groaci don't know. They're a very cultured, gentle people. You can Groaci. I think I can get past them all right." "What in the world—" "The Groaci won't waste any time destroying every piece of paper in indignation. "You're like a ... a...." "You and I are in a tight spot, Miss Meuhl. The logical next move for the Groaci is to dispose of both of us. We're the only ones who know touch with you via hand-phone." afternoon's conversation, along with the information I've given you. Beam it through on a mayday priority. Then tell the Groaci what you've done and sit tight. I think you'll be all right. It won't be easy to blast in here and anyway, they won't make things worse by killing you. A force can be here in a week." "I'll do nothing of the sort! The Groaci are very fond of me! You ... Johnny-come-lately! Roughneck! Setting out to destroy—" "That's good," Retief said. "I don't think the Groaci can knock us off suited to diplomatic work." stepped to the local communicator. "I'm going to report this terrible thing to the Groaci at once, and A Groacian official appeared on the screen. the Groacian Autonomy, I herewith accredit you as Terrestrial Consul to Groac, in accordance with the advices transmitted to my government

<question>:
What are two examples of Groacian communication mechanisms?

<options>:
A Mandible snaps and throat-bladder bleats
B Mandible wiggles and eye clogs
C Jaw snaps and jugular cracks
D Jowl clacks and eye beats

<answer>:

A