Which of the following is not aromatic?

$A$ piece of iron is heated in a flame. It first becomes dull red, then becomes reddish yellow, and finally turns to white hot. The correct explanation for the above observation is possible by using:

Negation of the statement "The payment will be made if and only if the work is finished in time." is

An ideal gas of mass $m$ in a state $A$ goes to another state $B$ via three different processes as shown in the figure. If ${Q_1}, {Q_2}$ and ${Q_3}$ denote the heat absorbed by the gas along the three paths,then

The shield-shaped cotyledon seen in monocot seeds is known as:

Which one of the following pairs of geographical areas shows maximum biodiversity in our country?