Pores of sieve plates

Question

$\begin{array}{1 1}(a)\; \text{Connect cytoplasmic strands of adjacent sieve cells} \\ (b)\; \text{Connect companion cells with adjacent sieve cells} \\ (c)\; \text{Connect parenchyma cells with adjacent sieve tube cells} \\ (d)\; \text{All of the above} \end{array}$