
Passage: A thermal station has five valves that control the delivery of steam to the outside. The use of these valves must comply with the following operations.First, if you open the No. 1 valve, you must also open the No. 2 valve and close the No. 5. Second, if you open the No. 2 valve or the No. 5 valve, you have to close the No. 4 valve. Third, do not close the No. 3 and No. 4 valves at the same time.
Question: If you want to open valve No. 1, which of the followings valves should be opened at the same time?
A. A.Valve No.2 and Valve No.4
B. B.Valves No.3 and Valves No.5
C. C.Valve No.2 and Valve No.3
D. D.Valve No. 4 and Valve No. 5
Answer: