Final Answer:
The light right angle boom, which supports the 470 cylinder, is supported b. Horizontally.
Step-by-step explanation:
The statement indicates that the light right angle boom supports the 470 cylinder, and it is supported horizontally. In engineering and construction, the term "right angle" typically refers to a 90-degree angle. A horizontal support implies that the boom extends horizontally from a fixed point, providing stability to the 470 cylinder. This arrangement is common in various structural designs where horizontal support is essential for maintaining equilibrium. While vertical and diagonal supports have their applications, the specific mention of a "right angle" boom suggests a horizontal orientation in this context.
Option: B is the answer.