A shift in the demand for a product is likely to result from a change in:

Option(a) is wrong b/c a change in products price only changes quantity demanded, moving along the same demand curve .It does not shift the demand curve. Option (c) and (d) are also wrong b/c the prices of factors of production and production technology both can shift the supply curve and they can not shift the demand curve. Option (b) is right answer b/c change in expectations about the product may cause the demand curve to shift.}