8老师：你好！
我的case在lockbox又被reject了，这次是因为CSPA的问题.
请见以下uscis的邮件：
Because you are now over 21, you are no longer be able to file for derivative status as the child of the beneficiary of an approved petition, unless you believe you qualify to apply based upon the Child Status Protection Act (CSPA).
When you refile, and you believe you may qualify under CSPA. to ensure that your I-485 application is accepted and processed as a CSPA application, you would need to create a new first page for your I-485 application, to select ‘h’ and write that you are filing as a derivative beneficiary under CSPA, as shown below (as a derivative beneficiary under CSPA).
我确认过了我的CSPA age is eligible for apply I-485：
DOB: 8/21/1990
Priority date: 5/29/2002
Approval date: 5/30/2009
Visa bulletin current date: 4/3/2015
17 years 7 month 12 days
以上是我算出来的CSPA结果，请你帮忙看看是否正确。
Again，refresh your memory on my situation:
母亲是F4亲属移民过来的绿卡持有者，我本人现在持F1 OPT，以及是母亲的derivative beneficiary. 父亲还在中国，不会移民来美。
请问，这种情况下是否要写封申诉儿童保护法的信件给USCIS？以什么理由更能说服USCIS批准这个案子？
期盼您的答复。非常感谢！！