Correct Answer - A
Given, width of the slit `=10^(4) Å`
`=10^(4)xx10^(-10)m=10^(-6)m=1 mum`
Wavelength of (visible) sunlight varies from `4000 Å` to `8000 Å` As the width of slit is comparable to that of wavelength hence diffraction occurs with maxima at centre. So, at the centre all colours appear i.e., mixing of colours form white patch at the centre