单选题：The following question are related to the following shell script

The following question are related to the following shell script (with line numbers for easy reference)
```
1). dd if=/dev/zero of=myfs bs=1M count=2
2). mkfs.ext2 myfs
3). changeMN myfs #to change the manic number to the right value
4). mount –t myext2 –o loop myfs /mnt
5). mount
6). umount /mnt
7). mount –t ext2 –o loop myfs /mnt
```
The command in which line will cause an error? @[D](1)
A. Line 4
B. Line 5
C. Line 6
D. Line 7




A.Line 4
B.Line 5
C.Line 6
D.Line 7


答案：D