Here, (ada0) is my disk and (ada1) is my friend's.
I choose AUTO (UFS) option and then selected ENTIRE DISK and formatted the (ada1) disk in MBR. I noticed that it created 2 partitions of mnbsd (ufs and swap). And then the installation was successfully completed later.
Now my question is how to make this BSD filesystem manually using PARTITION editor in my own disk (ada0). Not matter what i type in Create Partition option, it wont let me do this.