The biologist discovered that from 1988 to 1993, the average beak size declined to pre-1981 levels. The reversal in beak size from 1988 to 1993 was most likely related to which of the following events? 
(A) A loss of food supply for the finches 
(B) The end of the drought 
(C) An increase in drought conditions 
(D) An increase in predators consuming finches



Answer :

assuming a drought happened from 1988-1993, b is the answer, the end of the drought would cause beak sizes to revert back due to the original food source coming back, causing natural selection and all that, leading to birds with the appropriate beak size from before 1988 to grow again