For distributions reported with code 3 in box 7 of the Form 1099-R, this question refers to the minimum retirement age specified by the retirement plan from which the distribution was made, which may or may not be age 59½, so you must refer to the plan agreement to find the answer. Distributions made prior to this age are treated as wages.
(It appears that when the developers created this page in the online version of TurboTax, they made the question ambiguous compared to the wording in the download version of TurboTax which asks, "What was the youngest age you could have retired and received a pension from your last employer if you hadn't become disabled.")