Which of the following characters represent affinities of Gnetum with Angiosperms and differences with Cycas and Pinus?

Question

$\begin{array}{1 1}\text{ a. Presence of xylem vessels and absence of archegonia} \\ \text{b.Perianth and two integuments} \\ \text{c.Embryo development and apical meristem} \\ \text{d.Absence of resin ducts and leaf venation.}\end{array}$