* For most academic settings: An A is the highest grade possible and is generally considered excellent and acceptable, even desirable.
* For specific individuals or situations: Someone might have personal standards higher than an A, or a specific situation might require a perfect score. An A might be unacceptable if it's below expectations for a scholarship, a job, or a personal goal.
So, while generally an A is exceptionally acceptable, it's not universally so. More information is needed to give a definitive answer.