No clear answer
If a question presents Carbamazepine and Gabapentine as options then you probably should choose Gabapentine unless there are other matters that you need to consider such as if it's partial epilepsy.
All the conventional anticonvulsants like Carbamzepine, Phenytoin, and Valproic acid have serious teratogenic effects and there's no clear preference.
The newer anticonvulsants such Gabapentine and Lamotrigine are claimed to have fewer side effects, however, that has not been clearly established so far.