Which of the following is/are true for an abstract class?
i) Abstract classes in PHP are declared with the help of abstract keyword.
ii) A class is declare abstract by using the keyword implements.
iii) It is a class that really isn’t supposed to ever be instantiated but instead serves as a base class.
iv) Attempting to instantiate an abstract class results in an error.
a) Only i)
b) Only iii)
c) ii) and iv)
d) ii), iii) and iv)

Answer: a
Explanation: The abstract classes are the classes in which at least one method need to be abstract. Abstract classes in PHP are declared with the help of abstract keyword.