Looking at the picture, we have to find the full form of UFO. As stated in the last line- 'Our artist purchased this picture of the UFO recently spotted over Rajasthan...' This explains to us that the object was above Rajasthan. The picture shows how the UFO looks but doesn't give the full form of UFO, let's look at the options.
Option A - 'Union Foreign Office' is incorrect as the office can't be over Rajasthan. Also, UFO is a scientific abbreviation, and its full form is 'Unidentified Flying Object'. Hence, option A is incorrect.
Option B - 'Unidentified Force Object' is incorrect, because if the object is unidentified, how can we say if it has force? Also, it is logically incorrect. Also, UFO is a scientific abbreviation, and its full form is 'Unidentified Flying Object'. Hence, option B is incorrect.
Option D - 'Unidentified Forced Object' is nearly the same as 'Unidentified Force Object'. Also, UFO is a scientific abbreviation, and its full form is 'Unidentified Flying Object'. Hence, option D is incorrect as well.
Option C - 'Unidentified Flying Object' is a scientific term and hence it is correct. The picture states 'over Rajasthan', so, 'flying' is the correct term here. Hence, option C is correct.