The pedigree chart below shows the individuals in a family who exhibit a certain trait. based on the info in the chart, which of the following provides the best evidence that this is a recessive trait? a. couple 3-4 in the 2nd generation produced children who are identical twins. b. couple 1-2 in the second generation produced children who do show the trait. c. couple 1-2 in the 1st generation produced children who do show the trait. d. couple 3-4 in the 2nd generation produced children who do not show the trait.