Drug X is used in the treatment of cardiac arrhythmias. It is not recommended for use in asthmatic patients because of effects on certain adrenoceptors. This drug is probably A: procainamide B: propranolol C: quinidine D: lidocaine E: phenytonin

Procainamide differs from quinidine in the following respects that A: it has little anticholinergic effect B: it can inhibit Na+ channel C: it has no α-adrenergic blocking activity D: it does not cause paradoxical tachycardia