_________, the leader's comments came a day after the party's performance in the region was not encouraging.

The blank requires an adverbial discourse marker describing the manner in which the leader's comments were made. 'Engagingly' (in a charming/interesting manner) fits as an introductory adverbial describing how the comments were delivered, despite the discouraging context. 'Despite' is a preposition needing a complement and cannot stand alone. 'Moreover' (in addition) does not fit since no prior point is being added to. 'Endearingly' is possible but 'engagingly' more naturally introduces public political comments. Therefore the answer is (b) Engagingly.