$\begin{array}{1 1}\text{a.Parthenogenesis, which is a form of apomixes.} \\ \text{b. parthenogenesis,which is a form of amphimixis } \\ \text{c. Adventitious embryony, which is a form of amphimixis.} \\ \text{d. Agamospermy, which is a form of amphimixis.} \end{array} $