You have a table of sales in your database. The columns of the table include : PurchaseDate and PurchaseAmount. You have decided to apply a discount of $5\%$ on purchases made in the month of December. You are going to design a query where you will be adding a calculated column that shows the discount applicable on each purchase. If the purchase is not made in December, no discount should be applied. Choose the correct expression to calculate the discount:

Group of answer choices

Discount: If$($DatePart$("$m$",[$PurchaseDate$])=12,[$PurchaseAmount$]*0\mathrm{.}05,0)$

Discount: IIf$($DatePart$("$m$",[$PurchaseDate$])=12,[$PurchaseAmount$]*0\mathrm{.}05,0)$

Discount: If$($DatePart$("$m$",$PurchaseDate$)=12,$PurchaseAmount$*0\mathrm{.}05,0)$

Discount: IIf$($DatePart$("$yyyy$",[$PurchaseDate$])=12,[$PurchaseAmount$]*0\mathrm{.}05,0)$