To answer this question, the user needs to have knowledge of COBOL file processing clauses.

Option A: Record Not Found - This clause is used to detect if there are no more records beyond the point where a READ statement is executed. It is not an alternative to checking for file status = 10.

Option B: At End - This clause is used to detect the end of a file. It is a valid alternative to checking for file status = 10.

Option C: Duplicate Record - This clause is used to detect if there are duplicate records in a file. It is not an alternative to checking for file status = 10.

Option D: End Of File - This clause is used to detect the end of a file. It is a valid alternative to checking for file status = 10.

Option E: At Spaces - This clause is used to detect if a record contains only spaces. It is not an alternative to checking for file status = 10.

Therefore, the correct answer is:

The Answer is: B. At End