\textbf{135.} For which value of $a$, the angle between the tangent line to the circle $x^2 + y^2 - 2x + y = 1$ and the line $3x + 2y = a$ at their intersection point is $90°$?
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\hfill (1) $2$ \hfill (2) $3$ \hfill (3) $4$ \hfill (4) $5$ \hfill
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