Read the following extract carefully and answer the questions that follow :

                                                         ‘‘Proper’’ social roles

Here is a story from the Adi Parvan of the Mahabharata :

 Once Drona, a Brahmana who taught archery to the Kuru princes, was approached by Ekalavya, a forest-dwelling nishada (a hunting community). When Drona, who knew the dharma, refused to have him as his pupil, Ekalavya returned to the forest, prepared an image of Drona out of clay, and treating it as his teacher, began to practise on his own. In due course, he acquired great skill in archery. One day, the Kuru princes went hunting and their dog, wandering in the woods, came upon Ekalavya. When the dog smelt the dark nishada wrapped in black deer skin, his body caked with dirt, it began to bark. Annoyed, Ekalavya shot seven arrows into its mouth. When the dog returned to the Pandavas, they were amazed at this superb display of archery. They tracked down Ekalavya, who introduced himself as a pupil of Drona.

Drona had once told his favourite student Arjuna, that he would be unrivalled amongst his pupils. Arjuna now reminded Drona about this. Drona approached Ekalavya, who immediately acknowledged and honoured him as his teacher. When Drona demanded his right thumb as his fee, Ekalavya unhesitatingly cut it off and offered it. But thereafter, when he shot with his remaining fingers, he was no longer as fast as he had been before. Thus, Drona kept his word : no one was better than Arjuna.

(15.1) Why did Drona refuse to have Ekalavya as his pupil ?

(15.2) How did Ekalavya react to the demand of his Guru ?

(15.3) Mention two versions of Guru-Shishya Parampara mentioned in the given extract.