The correct answer is: C. Stretcher bond facing and double Flemish bond backing in each course
Single Flemish bond is a type of brickwork in which each course consists of alternating headers and stretchers, with the headers laid in the center of the course and the stretchers laid at the edges. The facing of a single Flemish bond wall is made of stretchers, while the backing is made of double Flemish bond. Double Flemish bond is a type of brickwork in which each course consists of alternating headers and stretchers, with the headers laid at the edges of the course and the stretchers laid in the center.
Here is a diagram of single Flemish bond:
Here is a diagram of double Flemish bond:
As you can see, single Flemish bond and double Flemish bond are very similar, except that in single Flemish bond, the headers are laid in the center of the course, while in double Flemish bond, the headers are laid at the edges of the course.
The reason why single Flemish bond is made with stretchers on the facing and double Flemish bond on the backing is because stretchers are easier to lay than headers. Headers have to be cut to fit, while stretchers can be laid directly from the brick. This makes it faster and easier to lay a single Flemish bond wall.
Single Flemish bond is a very common type of brickwork, and it is used for a variety of applications, including walls, chimneys, and fireplaces. It is a strong and durable type of brickwork, and it is also attractive.