Step 1 :Let's denote the regions as follows: I: Only in A, II: Only in B, III: Only in C, IV: In A and B, but not C, V: In A and C, but not B, VI: In B and C, but not A, VII: In A, B, and C, VIII: In U, but not in A, B, or C
Step 2 :We know that \(n(A \cap B \cap C) = 5\), so VII = 5
Step 3 :We also know that \(n(A \cap B) = 10\), but this includes the elements that are also in C. So, IV = \(n(A \cap B) - VII = 10 - 5 = 5\)
Step 4 :Similarly, V = \(n(A \cap C) - VII = 11 - 5 = 6\), and VI = \(n(B \cap C) - VII = 7 - 5 = 2\)
Step 5 :Now, we can find the number of elements that are only in A, B, or C. I = \(n(A) - IV - V - VII = 24 - 5 - 6 - 5 = 8\). II = \(n(B) - IV - VI - VII = 20 - 5 - 2 - 5 = 8\). III = \(n(C) - V - VI - VII = 18 - 6 - 2 - 5 = 5\)
Step 6 :Finally, we can find the number of elements that are in U but not in A, B, or C. VIII = \(n(U) - I - II - III - IV - V - VI - VII = 43 - 8 - 8 - 5 - 5 - 6 - 2 - 5 = 4\)
Step 7 :So, the number of elements in regions I, II, III, IV, V, VI, VII, VIII are 8, 8, 5, 5, 6, 2, 5, 4, respectively. Therefore, the answer is \(\boxed{A}\)