Correct answer 2.) emboldened
Encased refers to the idea that something is enclosed, which does not make sense to be enclosed when he is trying to speak French in Paris.
Emboldened, the correct answer, means that you are bold and empowered to be bold.
Ensnared implies that you are caught in something like a trap.
And Encroached means an intrusion. In this case he did not intrude to speak French in Paris.
