Answer:
Option C
Step-by-step explanation:
Option A: In a rhombus, the diagonals bisect opposite angles.
It is always true.
Option B : In a rhombus, the diagonals are perpendicular.
It is always True.
Option C : . In a rhombus, the diagonals are congruent.
It is not always true. If the diagonals become congruent then It becomes square.
Option D: In a rhombus, all four sides are congruent.
It is always True.
Hence Option C is the statement which is not always true.
