Omo's brother won a RADIO.

Analyze the question: This tests emphatic stress (focus) in oral English. The capitalised word, RADIO, is the new or corrected information in the answer. The question it answers must therefore contain a different item in that same position, which the answer then corrects.

Concept: Emphatic stress marks the word that contrasts with what the questioner assumed. For example, "Did he buy a phone?" is answered with "He bought a RADIO," correcting "phone" to "radio."

Step-by-step solution:

Statement: Omo's brother won a RADIO. The stress is on the object, so the questioner must have had the wrong object in mind.

• A. Did Omo's brother lose a radio? The wrong item here is the verb (lose vs. win). The answer would stress WON, not RADIO.
• B. Did Omo's sister win a radio? The wrong item is the person (sister vs. brother). The answer would stress BROTHER.
• C. Did Omo's brother win a phone? The wrong item is the object (phone). The answer corrects it with "a RADIO." ✔
• D. Did Tayo's brother win a radio? The wrong item is the owner's name (Tayo vs. Omo). The answer would stress OMO'S.

Tip: Find the word in capitals, then look for the option where that exact slot is different (the one the answer corrects). In every other option, the wrong detail is somewhere else, so the stress would fall on a different word.