Which statement uses a correct open/close code pair for the valve?

Which statement uses a correct open/close code pair for the valve?

• A. Opens at 3433 and closes at 3133.
• B. Opens at 3534 and closes at 3133.
• C. Opens at 3633 and closes at 3133.
• D. Opens at 3533 and closes at 3133.

Answer: (D)

Understanding how codes pair: each valve has an open code and a close code that are tied to the same valve. The middle two digits identify which valve is being controlled, while the last two digits indicate the action (open or close). The given close code is 3133, so the open code must reference the same valve in the middle digits. Among the options, only the one with 53 in the middle matches that valve, yielding 3533 for opening. That pairs with 3133 for closing, forming a valid open/close pair for this valve. The other openings point to different valves (43 or 63) or alter the action digits, so they don’t pair correctly with the provided close code.

Understanding how codes pair: each valve has an open code and a close code that are tied to the same valve. The middle two digits identify which valve is being controlled, while the last two digits indicate the action (open or close). The given close code is 3133, so the open code must reference the same valve in the middle digits. Among the options, only the one with 53 in the middle matches that valve, yielding 3533 for opening. That pairs with 3133 for closing, forming a valid open/close pair for this valve. The other openings point to different valves (43 or 63) or alter the action digits, so they don’t pair correctly with the provided close code.