From both phylogenetic and ontogenetic points of view,which tissue is regarded as the most primitive?

Xylem tissue is composed of

$I.$ Made up of sclerenchymatous cells
$II.$ Generally absent in primary phloem
$III.$ Much elongated and pointed
Given above characters belong to which of the following?

Which of the following is a mechanical tissue found in living cells?

Aerenchyma is formed in the tissue of

$A$ common structural feature of vessel elements and sieve tube elements is