Concept:The sentence has misplacement of the words "affair" and "trusted". Swapping them gives a meaningful sentence.
Explanation:Read the original sentence: "Shocked by her husband’s betrayal, the heartbroken woman couldn’t believe that the man she affair had been having a year-long trusted."
The phrase "the man she affair" is incorrect. The correct phrase should be "the man she trusted".
Similarly, "a year-long trusted" is wrong; it should be "a year-long affair".
Therefore, the words at positions (C) and (D) need to be interchanged.
The correct sentence is: "Shocked by her husband’s betrayal, the heartbroken woman couldn’t believe that the man she trusted had been having a year-long affair."
Hence, the required arrangement is C-D.
Answer:Option 4: C-D