In an embryo sac, the cells that degenerate after fertilisation are

1. synergids and primary endosperm cell

2. synergids and antipodals

3. antipodals and primary endosperm cell

4. egg and antipodals

(b) In unfertilized embryo sac, the antipodals and synergids are distinctly present at chalazal end and micropylar end respectively While, in fertilised embryo sac antipodals and synergids gradually degenerate after the formation of zygote.
Page 27, XII NCERT