Consider the following statements in case of Young’s double slit experiment. (a) A slit S is necessary if we use an ordinary extended source of light (b) A slit S is not needed if we use an ordinary but well collimated beam of light (c) A slit S is not needed if we use an spatially coherent source of light. Which of the above statements are correct ?

Options

A. (a) and (c)
B. (b) and (c)
C. (a) and (b)
D. (a),(b) and (c).