The term implies that the type’s data can be accessed only through methods.

a. abstract type library
b. advanced data type
c. abstract definition type
d. abstract data type

D. abstract data type

Explanation:

Abstract data type is a data type whose implementation is embedded behind an abstraction. They can be worked via methods and functions but their  specification is abstracted.

Lists and Stacks can be given as examples of abstract data types.

Abstract data type can be considered as the opposite of Concrete Data Type (CDT).

i think the answer would be a

answeruse the nslookup utility;