a
\(95\%\,\,H_2SO_4\) by weight means \(100\,g\,\,H_2SO_4\) solution contains \(95\,g\) \(H_2SO_4\) by mass.

Molar mass of \(H_2SO_4\) \(=\,98\,g\,mol^{-1}\)

Moles in \(95\,g\) \(=\,\frac {95}{98}\,=\,0.969\,mole\)

Volume of \(100\,g\,\,H_2SO_4\)

\(=\,\frac {mass}{density}\) \(=\frac {100\,g}{1.834\,g\,cm^{-3}}\)

\(=\,54.52\,cm^3\) \(=\,54.52\times 10^{-3}\,L\)

Molarity \(=\,\frac {Moles\,of\,solute}{Volume\, of\, Solute \,in\,L}\)

\(=\,\frac {0.969}{54.52\times 10^{-3}}=\,17.8\,M\)