Alertly vs raptly

[micaelo]

In the following fill-in-the-gap exercise:
Some other nations did the occasional scrawl when listening ..., but the British were undoubtedly the most compulsive of all those attending.

a ecstatically B calmly C raptly D alertly
Obviously, the correct option is C raptly, but I was wondering about the meaning of "listening alertly", I feel it means to listen as if expecting the other person to make a mistake or say something objectionable. Am I correct here? Thank you.

 

[Anglika]

Rather more that the listeners are intending to be aware of anything unusual or unexpected

 

[apex2000]

In the following fill-in-the-gap exercise:
Some other nations did the occasional scrawl when listening ..., but the British were undoubtedly the most compulsive of all those attending.

a ecstatically B calmly C raptly D alertly
Obviously, the correct option is C raptly, but I was wondering about the meaning of "listening alertly", I feel it means to listen as if expecting the other person to make a mistake or say something objectionable. Am I correct here? Thank you.

Obviously C? Option B would fit better, but the use of 'compulsive' is odd; compusive what? Speakers? Listeners? Writers? Option D might fit except 'occasional scrawl' implies a less attentive approach.