Two electrons occupying the same orbital are distinguished by

The equation of the common tangent to the curves $y^2 = 8x$ and $xy = -1$ is

$X$ - In deep-sea hydrothermal vents,the average temperature is between $25^{\circ}C$ to $30^{\circ}C$.
$Y$ - Reptiles and amphibians are eurythermal.

The meristematic tissue responsible for the increase in the girth of a tree trunk is:

The angle between the lines joining the origin to the points of intersection of the line $x + 2y + 1 = 0$ and the curve $2x^2 - 2xy + 3y^2 + 2x - y - 1 = 0$ is

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. Tranquilizers	$I$. Anti blood clotting
$B$. Aspirin	$II$. Salvarsan
$C$. Antibiotic	$III$. Antidepressant drugs
$D$. Antiseptic	$IV$. Soframicine

Choose the correct answer from the options given below: