Concept:This is a third conditional sentence. It describes an unreal situation in the past and its imagined result. The main clause must use "would have" (not "will have").Explanation:The sentence starts with "If he had followed" – this is the past perfect tense for the condition. The consequence part should follow the pattern: "would + have + past participle". The error is in part (c): "he will not have faced". The word "will" is for future tense, but we need the hypothetical past form "would". So correct part (c) is "he would not have faced". No other part has any mistake. The correct sentence is: "If he had followed his father's advice, he would not have faced this worrying situation."Answer:A. c