1A) and B)
coz,
if d =lambda...then, we wud have just one maxima at the centre...there wud be no maxima anywhere else becoz, the maximum path diff. that can be obtained is d which is at y=infinity... so the only next possible maxima cud be at +-infinity...so A) is rite..
same way if lambda<d<2 lambda...there wud be 1 point between infinity and zero where the pathdifference wud be lambda...so we have another maxima somewhere...hence even B) is rite...
C) and D) are wrong coz the intensity of the minimas are always zero..so no increase...
