Python's mechanism allows the programmer to view an interface for an entire class or an individual method, at the shell prompt.

The question above has multiple choices as follows;

a. API

b. docstring

c. help

d. man

Well, I am stuck between B and C. I’ll however settle for (B) docstring.

Python docstrings provide an easier way to associate documentation with python classes, modules and functions. The interactive help function on the other is built in and is intended for interactive use. This function exists to view help interactively. With the help feature, you can quickly learn classes, modules, functions and many more.

answer; i believe the answer you're looking for is (nanotechnology);

that without the operating systems you would have to control and synchronize computer hardware.