Question $19$ of $20$ :Select the best answer for the question$\mathrm{.}19.$ Which of the following is a requirement for turnbuckles?O A$.$ They must be wired or clipped. B$.$ They must be lubricated.O C$.$ They must all have the same barrel length.D$.$ They must have more than three threads showing at either end of the barrel. Mark for review $($Will be highlighted on the review page$)$