Which of the following has the lowest melting point?

The maximum value of $\sin (\cos (\tan x))$ is

The quadratic equations $x^2 - 6x + a = 0$ and $x^2 - cx + 6 = 0$ have one root in common. The other roots of the first and second equations are integers in the ratio $4 : 3$. Then the common root is

Match the following columns and select the correct option:

$(a)$ Eosinophils	$(i)$ Immune response
$(b)$ Basophils	$(ii)$ Phagocytosis
$(c)$ Neutrophils	$(iii)$ Release histaminase enzyme
$(d)$ Lymphocytes	$(iv)$ Release granules containing histamine

$(a)\quad (b)\quad (c)\quad (d)$

The number of ways of choosing $10$ objects out of $31$ objects,of which $10$ are identical and the remaining $21$ are distinct,is

The figure shows the volume $V$ versus temperature $T$ graphs for a certain mass of a perfect gas at two constant pressures of $P_1$ and $P_2$. What inference can you draw from the graphs?