Biologist: Marine animals known as box jellyfish have eyes with well-formed lenses capable of producing sharp images that reveal fine detail. But the box jellyfish' s retinas are too far forward to receive a clear image, so these jellyfish can receive only a blurry image that reveals prominent features of objects but not fine detail. This example shows that eyes are adapted only to an animal' s needs rather than to some abstract sense of how a good eye would be designed. The argument requires assuming which one of the following?
A: Box jellyfish developed from jellyfish whose retinas received clear images.
B: Box jellyfish have a need to detect prominent features of objects but not fine details.
C: Box jellyfish would benefit from having retinas that allowed their eyes to focus more sharply.
D: Box jellyfish use vision as their main means of detecting prey.
Choose A, B, C or D as your solution.
B