Read the passage given below and answer the questions/ complete the statements that follow by choosing the most appropriate options from the given ones.

The gorilla is something of a paradox in the African scene. One thinks one knows him very well. For a hundred years or more he has been killed, captured and imprisoned in zoos. His bones have been mounted in natural history museums everywhere, and he has always exerted a strong fascination upon scientists and romantics alike. He is the stereotyped monster of the horror films and the adventure books, and an obvious (though not perhaps strictly scientific) link with our ancestral past.

Yet the fact is we know very little about gorillas. No really satisfactory photograph has ever been taken of one in a wild state, no zoologist, however intrepid, has been able to keep the animal under close and constant observation in the dark jungles in which it lives. Carl Akley, the American naturalist, led two expeditions to these volcanoes in the nineteen twenties, and now lies buried here among the animals he loved so well. But even he was unable to discover how long the gorilla lives or how or why he dies, nor was he able to define the exact social pattern of the family groups, or indicate the final extent of their intelligence. All this and many other things remain almost as much a mystery as they were when a French explorer first described the animal to the civilised world a century ago. The Abominable Snowman who haunts the imagination of climbers in the Himalayas is hardly more elusive. The little that is known about gorillas certainly makes you want to know a great deal more. Sir Julian Huxley has recorded that thrice in the London zoo he saw an eighteen-month-old specimen trace the outline of its own shadow with its finger.