Which of the following has the highest water holding capacity?

Correct option is A

The correct answer is Clay soil.
Clay soils have very fine particles that trap water effectively, leading to a high water holding capacity compared to sandy or loamy soils. 
Additional Information
(b) Sandy soil:
Sandy soils have large particles with large spaces between them, allowing water to drain quickly, resulting in low water holding capacity. 
(c) Loamy soil:
Loamy soils are a mixture of sand, silt, and clay. While they have a higher water holding capacity than sandy soils, they are not as high as clay soils due to their smaller particle size distribution.