Complex tissue includes

Companion cells in plants are associated with

Contractile tissues have the following features
$(i)$ Mesodermal in origin
$(ii)$ They contain stretch receptors.
$(iii)$ Rhythmic contractions are seen in them
$(iv)$ They do not fatigue during the life of the animal
Which of the above are characteristics of sphincters?

A hundred year old tree which shows well marked annual rings in its trunk will have

In dicot stem, secondary xylem lie towards the ...$A$... and secondary phloem lie towards the ...$B$...

Choose the correct combination of options for $A$ and $B$