The number of moles of nitric acid can be obtained by multiplying the molarity with volume\\\\(M\ imes V=\\\\)Moles of \\\\(\\displaystyle HNO_{3}=\\frac{250\ imes 2}{1000}=0.5\\\\)The mass of nitric acid can be obtained by multiplying the number of mols with molar mass and dividing with percentage concentration.\\\\(\ herefore HNO_{3}\\\\) required \\\\(=\\displaystyle 0.5\ imes 63\ imes \\frac{100}{70}=45\\:g\\\\)Thus 45.0 g conc. \\\\(HNO_{3}\\\\) of concentrated nitric acid solution should be used to prepare 250 mL of 2.0 M \\\\(HNO_{3}\\\\).Hence, the correct option is \\\\(A\\\\).