Read these lines: "Diligence and attention soon gave him the knack of it, and he strode down the street with his mouth full of harmony and his soul full of gratitude. He felt much as an astronomer feels who has discovered a new planet, no doubt, as far as strong, deep, unalloyed pleasure is concerned, the advantage was with the boy, not the astronomer." Comparing the boy to an astronomer mainly shows

1. What the boy has learned is a way of whistling, which is a very small thing. 2. It is set beside the discovery of a new planet, which is about as large as a discovery gets. 3. The comparison is then pushed further, with the pleasure said to run in the boy's favour rather than the astronomer's. 4. So the point is the size of the feeling, not the size of the achievement, option D. 5. Option A takes the astronomer literally, but the boy is never said to look at the sky. _Source: Mark Twain, The Adventures of Tom Sawyer (1876), public domain_