Question 487 Deck General

The correct answer is C) Rider block tagline system. The rider block tagline system is an optional component of a twin crane set as shown in illustration D047DG. This system helps control the lateral movement of the rider block, which is used to transfer loads between the two cranes. The boom assembly and hook block assembly are essential components of a twin crane set and are not optional. The other answer choices, A) Boom assembly and B) Hook block assembly, are incorrect because these are required components of a twin crane set, not optional. The option D) All of the above is also incorrect because the rider block tagline system is the only optional component among the choices provided.