Choose the correct labellings for the parts $X, Y$ and $Z$ in the given figure of the stages in embryo development in a dicot:
 

The suspensor cell, which lies towards the micropylar end, is divided by transverse divisions to constitute 6-10 celled suspensor. Out of these eight cells, the lower four cells of the octant away from the suspensor give rise to the plumule and the two cotyledons, while the above four cells of the octant near the suspensor form the hypocotyl and the stele of radicle