I choose the third comment.
The reason why I would do this, I think because it was a comment on the positive and negative creative and useful in improving myself.
Positive feedback is a useful comment makes Feel comfortable with the work done, to build support for the next time.
It is really polite and nice words. For instructions that do not break the feelings of the recipient. He wrote it nicely and importantly he wrote the problems that he saw in the text indirectly. He encouraged people works more than he would say something directly. As a result, the recipient is not afraid to correct his work. As a result, the recipient is not afraid to correct his work. Not cause bias in the work and make the recipient feel that English is not difficult to learn the next.