Which of the following statements regarding abstract methods is false?

a$.$ An abstract class can have instances created using the constructor of the abstract class.

b$.$ An abstract class can be extended.

c$.$ A subclass of a non$-$abstract superclass can be abstract$.$

d$.$ A subclass can override a concrete method in a superclass to declare it abstract$.$

e$.$ An abstract class can be used as a data type.