Which of the following shows the correct first step to prove the following by mathematical induction? 3 + 11 + 19 + 27 + … + (8n - 5) = n(4n - 1) a) 3 + 11 + 19 + 27 + … + (8 • 1 - 5) = 1(4 • 1 - 1) b) 8 • 1 - 5 = 1(4 • 1 - 1) c) 3 + 11 + 19 + 27 + … + (8k - 5) = k(4k - 1) d) 3 + 11 + 19 + 27 + … + (8k - 5) + [8(k + 1) - 5] = (k + 1)[4(k + 1) - 1]