Which of the following electromagnetic waves/rays has the minimum frequency?

Microwaves, Radio waves, Ultraviolet rays, X-rays

Correct option is C

​$$\begin{array}{|c|c|c|}\hline\textbf{Type of Radiation} & \textbf{Frequency Range (Hz)} & \textbf{Wavelength Range} \\\hline\text{infrared} & 10^{13} - 10^{14} & 25\,\mu\text{m} - 2.5\,\mu\text{m} \\\text{radio waves} & < 3 \times 10^{11} & > 1\,\text{mm} \\\text{visible} & 4 \times 10^{14} - 7.5 \times 10^{14} & 750\,\text{nm} - 400\,\text{nm} \\\text{x-rays} & 10^{17} - 10^{20} & 1\,\text{nm} - 1\,\text{pm} \\\text{gamma-rays} & 10^{20} - 10^{24} & < 10^{-12}\,\text{m} \\\text{near-infrared} & 1 \times 10^{14} - 4 \times 10^{14} & 2.5\,\mu\text{m} - 750\,\text{nm} \\\text{microwaves} & 3 \times 10^{11} - 10^{13} & 1\,\text{mm} - 25\,\mu\text{m} \\\text{ultraviolet} & 10^{15} - 10^{17} & 400\,\text{nm} - 1\,\text{nm} \\\hline\end{array}$$​​