It is best to have knowledge of geomantic omen in 90 flat dark halls.

Scheme 1: The cost is low, and a solid partition wall can be made at the entrance with a carved mirror in the middle. Change bathroom door to an arrow.

Option 2: completely change AB into a hall, divide C into a bedroom aisle, change the originally gloomy hall window into a door, change the D bedroom door into an aisle as a secret door, and change the bathroom door into an arrow.