Explanation

(d) The degree Celsius ($℃$) scale was devised by dividing the range of temperature between the freezing and boiling temperature of pure water at standard atmospheric conditions into 100 equals parts.
For Fahrenheit scale.
Boiling point=$212℉$,
Freezing point=$32{^\circ}$
$\therefore$ Difference of $100℃ = difference\ of\ (212{^\circ} - 32{^\circ}) = 180℉$
$\therefore$ Difference of $30{^\circ} = \ \frac{180}{100}\ \times \ 30 = 54{^\circ}$