1. interface DoStuff2 {  2. float getRange（int low， int high）； }  3.  4. interface DoMore {  5. float getAvg（int a， int b， int c）； }  6.  7. abstract class DoAbstract implements DoStuff2， DoMore { }  8.  9. class DoStuff implements DoStuff2 {  10. public float getRange（int x， int y） { return 3.14f； } }  11.  12. interface DoAll extends DoMore {  13. float getAvg（int a， int b， int c， int d）； }  What is the result？（） 

• A、 The file will compile without error.
• B、 Compilation fails. Only line 7 contains an error.
• C、 Compilation fails. Only line 12 contains an error.
• D、 Compilation fails. Only line 13 contains an error.
• E、 Compilation fails. Only lines 7 and 12 contain errors.
• F、 Compilation fails. Only lines 7 and 13 contain errors.
• G、 Compilation fails. Lines 7， 12， and 13 contain errors.