B would be considered the most positive of the options given.
The theme is A birthday of my life
Since a participle takes the form: verb + -ing, the only word in this sentence which has such a form is B, 'challenging'. 'Puzzle' is a noun, 'crossword' is an adjective, 'created' is a verb.
Answer:
mInecraft (Lol)
The design is very brilliant implementing a lego feel along with some real life visual such as grass, animals, and certain wood. Being a blocky sort of game with no type of ahem "Violence Aftermaths to the creatures/mobs" it is kid friendly but offers visuals pleasing to adults alike so yeah enjoy your answer sir or Ma'am :)