State whether the following statements are True or False.
$(a)$. A concave lens can be used to produce an enlarged and erect image.
$(b)$. A convex lens always produces a real image.
$(c)$. The sides of an object and its image formed by a concave mirror are always interchanged.
$(d)$. Art object can be seen only if it emits light.

$(a)$. A concave lens can be used to produce an enlarged and erect image.                                                                                                    [False]

$(b)$. A convex lens always produces a real image.                 [False]

$(c)$. The sides of an object and its image formed by a concave mirror are always interchanged.                                                                 [True]

$(d)$. Art object can be seen only if it emits light.                    [False]