Hi Kartik,

Briefly, the passage says that there are many companies who are making money by falsely sueing other Software companies under the banner of Patent Violation just to make money.
As this is an intellectual property, it is a grey area where taking decisions is always tough.Due to this most of the companies prefer to settle the issue outside the court by paying to the company filing a false patent infringement lawsuit.

Answers-
A. Out of context. You cannot summarize this soln from the passage.
B. Out of context
C. Nowhere the process of obtaining rights is given in the passage.
D. As the passage is taking about issues related to infringement and in the question the author has "Cautioned" against something. This option says that if companies have not done enough to protect their IPR then these troublesome companies might create a problem releated to Patent Infringement.
E. Software use does not matter, its the source code on which the whole issue is discussed.

Hope this proves useful.