Answer:
The correct option is 1. The diagonals of a rhombus are always perpendicular.
Explanation:
A quadrilateral is rhombus if the opposite sides are parallel, opposite acute and obtuse angles are equal, and four equal sides.
The line segment jointing the opposite vertices is known as diagonal.
According to the property of rhombus, the diagonals of a rhombus are perpendicular bisector of each other.
The diagonals of a rhombus are always perpendicular. Therefore the correct option is 1.