In the following question, sentence given with blank is to be filled in with an appropriate word. Select the correct alternative out of the four and indicate it by selecting the appropriate option.
The relocation of the car factory to our struggling town is an economic __________

The sentence requires a word that means a timely benefit or blessing for the struggling town.
Boon means something that is very helpful or brings good fortune. "Economic boon" is a standard and highly appropriate collocation here.

Good, donation, and present do not fit contextually or idiomatically in this sentence structure.