My opinion is the answers A and D. I would choose A if you can only choose one, though.
Answer:
system software is the software which control overall operation of the computer . For eg. Ms.dos ,window 2003 ,etc whereas application software is a software which work on the top of operating system to solve number of problems .For eg. Ms.word,Ms.excel,etc
Data visualization
Data visualization is a good starting point for data mining. There are several approaches to data mining that supports smart decisions. Data visualization places data in a visual context. It extracts the data in a clear and understandable way without any form of reading or writing. Results are displayed in the form of pie charts, graphs, and any other statistical representation. Such multidimensional views of data aid in developing a preliminary understanding of the trends that are hidden in the data set.
Answer:
toString is right Answer
Explanation:
If you want to represent any object as a string, toString() method comes into existence.
The toString() method returns the string representation of the object.
If you print any object, java compiler internally invokes the toString() method on the object. So overriding the toString() method, returns the desired output, it can be the state of an object etc. depends on your implementation.