Correct Answer - A
Given, discount `=25%" of MP"`
`SP=Rs. 1,200`
`impliesMP-"discount Discount"=1200`
`impliesMP-25%" of "MP=1200`
`implies75%" of "MP=1200`
`impliesMP=1200X(100)/(75)=1600`
Therefore, marked price of the article =Rs. 1,600.
Hence, the correct option is (a).