1. The problem describes a change in finch beak size distribution after a drought, where larger beaks became more common. 2. This is an example of natural selection, where environmental pressures affect survival and reproduction. 3. Important rules: - Traits that improve survival and reproduction tend to increase in frequency. - Random occurrences do not explain consistent directional changes. - Organisms do not develop traits on demand; traits are selected from existing variation. 4. Explanation: - Statement A is correct because finches with larger beaks were more likely to survive and reproduce due to better access to tougher seeds. - Statement C is correct because the drought created a selective pressure favoring larger beaks. 5. Statements B, D, and E are incorrect because: - B suggests randomness, which does not explain directional change. - D denies the effect of drought, which contradicts the observation. - E implies intentional development of traits, which is not how evolution works. Final answer: Statements A and C best explain the change.