Answer:
A) the code the application software uses to take advantage of code written by others
Step-by-step explanation:
An API is a tool widely used in the development of moderm software applications, it is basically a set of protocols and routines that specifies how the software application should interact with others. It provides the interface of the communucation link for the different parts of the program. The intent of APIs is for the simplification of software development and maintenance.