Refer to the given diagrammatic representation of distribution of water on Earth and select the correct statements for X, Y and Z.
(i) X is a persistent body of dense ice that is constantly moving under its own weight.
(ii) Y is found below the water table and rainwater is its main source.
(iii) Z is an important source of water to the perennial rivers.
A (i) and (ii) only
B (ii) and (iii) only
C (i) and (iii) only
D (i), (ii) and (iii)