The correct option is
D 20.11
The models are represented according to the following rule:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1198308/original_611035.png)
So, expressing the given models as decimals, we get:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1200429/original_Screenshot_2021-06-24_at_9.51.16_AM.png)
The ascending order of the decimals is 1.12 < 1.56 < 12.43 < 21.23.
Hence,
The largest decimal = A = 21.23
The smallest decimal = D = 1.12
Now, to calculate the difference between the largest decimal and the smallest decimal, we calculate the value of A - D.
Calculating A - D using models, we get:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1198310/original_615778%282%29.png)
The final representation of A - D contains 2 cubes, 0 flats, 1 rod, and 1 block.
So, the value of A - D is 20.11.
∴ The difference between the largest and the smallest decimals in the given representation is 20.11.