\textbf{140.} In the graph below, which is the minimum vertex cover?
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\textit{[Figure: Graph with vertices a, b, c, d, e, f, g, h, i, j and various edges]}
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(1) $\{b, h\}$\\
(2) $\{b, g, i\}$\\
(3) $\{a, c, h\}$\\
(4) $\{a, c, f, j\}$
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