Ans: (D)
Hint: Let the point intersection be \((\alpha, \beta)\).
so, \(\frac{\alpha}{a}+\frac{\beta}{b}=k\) and \(\frac{\alpha}{a}-\frac{\beta}{b}=\frac{1}{k}\)
\(\Rightarrow \frac{\alpha^{2}}{a^{2}}-\frac{\beta^{2}}{b^{2}}=1\)
\(\therefore\) Locus \(: \frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1\) which is equation of a hyperbola.