Which of the following is one of the reasons many middle-aged workers are delaying their retirement plans? Select one: a. the increase of retirement age to 75 years b. the increasing opportunity for middle-aged professionals c. the increased productive health owing to medical advancements d. the decline in definedWhich of the following is one of the reasons many middle-aged workers are delaying their retirement plans? Select one: a. the increase of retirement age to 75 years b. the increasing opportunity for middle-aged professionals c. the increased productive health owing to medical advancements d. the decline in defined-benefit pensions-benefit pensions