Top shaped multiciliated male gametes and mature seeds with one embryo having two cotyledon are characteristic features of

1. Cycas
   
2. Conifers
   
3. Gamopetalous angiosperm
   
4. Polypetalous angiosperms
   

The correct option is A Cycas

Cycads
Cycads is a group of gymnosperms, which have top shaped multiciliated male gametes (largest male gamete) and each mature seed of these plants contain one embryo and two cotyledons. Examples include Cycas.