The correct answer is B: In fractions of transmission line electrical wavelength. The wavelength scales on a Smith chart are calibrated in fractions of transmission line electrical wavelength. These scales show distance along a transmission line in terms of wavelengths. The Smith chart has wavelength scales around the perimeter that show distance along a transmission line. These scales are calibrated in fractions of electrical wavelength (like 0.0λ, 0.1λ, 0.2λ, etc.). As you move around the chart (representing moving along a transmission line), you can read the distance in wavelengths from these scales. The scales typically go from 0 to 0.5 wavelengths (half a wavelength), since impedance repeats every half-wavelength. These wavelength scales are essential for determining stub lengths and transmission line lengths in matching network design.