A isnt necessary because what if it molts once every two years and it has two sections? we will still be able to tell that the rattle snake is 4. Negating this doesnt ruin the argument which is "Rattlesnakes do not molt exactly once a year. E is necessary. Using this example by negating E becuase if rattle snakes molted more when there is more food and less when there is less food then we wouldnt be able to tell the age because lets say one snake lives near a bunch of food, and one live near little food. The first one would be much "older" under this principle and this would ruin the argument that we can tell the age based off the number of sections.

So... unless indicates group 3 which we negate, sufficient. How do we know to use this rule and exception formula? #feedback

greatly said. Thank you for posting this comment