Choose the correct answers from the alternatives given.
The perisperm is the remaining

Perisperm nutritive tissue of seed derived from the nucellus and deposited externally to the embryo sac distinguished from the endosperm. A layer of nutritive tissue in the seed of certain flowering plants that are derived from the nucellus and surrounds the embryo. In seeds of some plants remnants of nucellus is persistent. This residual, persistent nucellus is called perisperm.

So, the correct option is, 'nucellus'.