The popular belief that a snake's age can be determined by counting the number of layers of scales on its body is generally true. However, to help regulate its internal temperature, the outermost layers of scales of the Black Mamba snake often peel away when the temperature exceeding 120 degrees Fahrenheit, leaving the snake with fewer layers of scales than it would otherwise have. So only if the temperature in the Black Mamba's environment never exceeds 120 degrees Fahrenheit will its layers be a reliable measure of the snake's age.
Which of the following is an assumption on which the argument above depends?
A) The growth of new layers of scales in a snake is not a function of levels of its basal metabolic rate.
B) Only the Black Mamba loses layers of scales because of excessive heat.
C) One day of temperatures above 120 degrees Fahrenheit will cause the Black Mamba snake to lose a layer of scales.
D) The layers of scales of all snakes are of uniform thickness.
E) The number of layers of scales that will be lost when the temperature exceeds 120 degrees Fahrenheit is not predictable.
To encourage discussions OA later
Conclusion :- The method is reliable only if the temperature does not exceed 120F
Prethinking :- There is no other method to determine the layers lost when temperature rises.
Option A - Out of Scope, we are concerned with lost layers
Option B :- Out of scope, even if other snakes also lose, our argument is focused on Mamba snake
Option C :- Out of scope, we are not concerned with how much time it takes for layers to peel off, we are concerned with the count of no of layers lost.
Option D :- out of scope
Option E :- Correct. Negating this breaks the conclusion as we will be able to determine the age even if the temperature rises above 120F.
IMO :- E