\textbf{118.} From the relation $x^2y - y^2 - 2\sqrt{x} + 4 = 0$, the value of $\dfrac{d^2y}{dx^2}$ at the point $(1, 2)$ is which of the following?
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(1) $\dfrac{7}{6}$ \hspace{4cm} (2) $\dfrac{8}{6}$\\[6pt]
(3) $\dfrac{11}{6}$ \hspace{4cm} (4) $\dfrac{13}{6}$
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