Δabc underwent a sequence of rigid transformations to give δa′b′c′. which transformations might have taken place? a. a reflection across the y-axis followed by a reflection across the x-axis b. a rotation 90° clockwise about the origin followed by a reflection across the x-axis c. a rotation 270° clockwise about the origin followed by a reflection across the x-axis d. a reflection across the x-axis followed by a reflection across the y-axis.