Select the correct answer. triangle abc underwent a sequence of transformations to give triangle a′b′c′. which transformations could not have taken place? a. a reflection across the line y = x followed by a reflection across the line y = -x b. a reflection across the x-axis followed by a reflection across the y-axis c. a rotation 180° clockwise about the origin followed by a reflection across the line y = x d. a reflection across the y-axis followed by a reflection across the x-axis