When judging whether the LSA is old or new, the serial number parameter and age

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When judging whether the LSA is old or new, the serial number parameter and age parameter will be used. What is the correct statement about these two parameters?
A. When the router receives two LSAS with the same sequence number and the same check sum, the smaller the age, the better
B. When the router receives an LSA with age set to 3600s, it indicates that the LSA is not available
C. If the sequence number of LSA reaches the end value of 0x7fffff, the current router will announce the LSA with age of 3600s
D. Both the sequence number and the age parameter can judge whether the LSA is old or new. The router has priority in comparing the sequence parameter, and the bigger the better

I would like to ask the answer to this question is to choose CD, a option is right, ah, help to see, thank you!