From the words or group of words lettered A to D, choose the one that best completes the sentence. The eldest son took a foolish decision which made him ......

Answer Details

The word that best completes the sentence is "forfeit". This is because the sentence talks about a foolish decision made by the eldest son, which resulted in the loss of his claim to an additional chieftain title. "Forfeit" means to give up something as a penalty for a mistake or wrongdoing, which fits the context of the sentence. Therefore, option D, "forfeit", is the correct answer.