Commercially useful surface fibers are obtained from which of the following?

Thorns,spines and prickles are

What do $P$ and $Q$ represent in the given figure?

Given below are two statements $:$
Statement $- I :$ The arrangement of ovules within the ovary is known as aestivation.
Statement $- II :$ The mode of arrangement of sepals and petals in floral bud with respect to the other members of the same whorl is known as placentation.
In the light of the above statements,choose the correct answer from the options given below $:$

Match the following columns:

Column-$I$ (Local Name)	Column-$II$ (Scientific Name)
$A$. China rose	$i$. Bougainvillea spectabilis
$B$. Lemon	$ii$. Allium cepa
$C$. Sunflower	$iii$. Hibiscus rosa-sinensis
$D$. Onion	$iv$. Citrus limon
$E$. Bougainvillea	$v$. Helianthus annuus
-	$vi$. Rosa indica

$Casuarina$ $equisetifolia$ is a