If the diagonals of parallelogram are along the lines $3x - 4y + 2 = 0$ and $4x + 3y - 10 = 0$, then the parallelogram is

For a parallelogram, if the diagonals are perpendicular, then it is a rhombus; if the diagonals are equal, then it is a rectangle; if both happen, it is a square. The slopes of the given diagonal lines are obtained by writing them in slope-intercept form. From $3x - 4y + 2 = 0$, $$y = \frac{3}{4}x + \frac{1}{2}$$ so its slope is $\frac{3}{4}$. From $4x + 3y - 10 = 0$, $$y = -\frac{4}{3}x + \frac{10}{3}$$ so its slope is $-\frac{4}{3}$. Their product is $$\frac{3}{4} \cdot \left(-\frac{4}{3}\right) = -1$$ Hence the diagonals are perpendicular. In a parallelogram, perpendicular diagonals imply the parallelogram is a rhombus. There is no information that the diagonals are equal, so we cannot conclude rectangle or square. Checking the options: the matching choice is rhombus.