Shape factor is a dimensionless quantity that provides information about the shape of an object. It is defined as the ratio of the surface area of the object to the square of its volume.

In the case of a hemispherical body placed on a flat surface, we can calculate the shape factor as follows:

1. Surface Area of the Hemisphere:
The surface area of a hemisphere can be calculated using the formula:
SA = 2πr²,
where r is the radius of the hemisphere.

2. Volume of the Hemisphere:
The volume of a hemisphere can be calculated using the formula:
V = (2/3)πr³.

3. Shape Factor:
The shape factor, SF, is given by the ratio of the surface area (SA) to the square of the volume (V²):
SF = SA / V².

Let's calculate the shape factor for a hemispherical body:

1. Surface Area:
The surface area of a hemisphere is given by:
SA = 2πr².

2. Volume:
The volume of a hemisphere is given by:
V = (2/3)πr³.

3. Shape Factor:
SF = SA / V².

Now, let's substitute the values and calculate the shape factor:

1. Surface Area:
SA = 2πr².

2. Volume:
V = (2/3)πr³.

3. Shape Factor:
SF = 2πr² / [(2/3)πr³]².

Simplifying the equation:
SF = 2πr² / (4/9)π²r⁶.

SF = (9/4) / r⁴.

From the equation, we can observe that the shape factor depends on the radius of the hemispherical body. As the radius increases, the shape factor decreases and vice versa.

In this case, the hemispherical body is placed on a flat surface with respect to itself. Therefore, the radius of the hemispherical body is the same as the radius of the flat surface.

Since the shape factor is (9/4) / r⁴, and r is not equal to zero, the shape factor cannot be zero.

Given that the correct answer is option 'C' (0.5), it means that the shape factor is 0.5, which implies that the radius of the hemispherical body is 1 unit.