Final answer:
The correct answer is d) all options listed. Procaine, although extensively used in dentistry for a number of years, had several limitations that made it less ideal as a local anesthetic. These limitations include a long onset time, quick wearing off, and a high potential for triggering allergic reactions.
Step-by-step explanation:
The correct answer is d) all options listed. Procaine, although extensively used in dentistry for a number of years, had several limitations that made it less ideal as a local anesthetic. Firstly, it took a long time to produce the desired anesthetic result. Secondly, it wore off quickly, leading to the need for frequent reapplication. Finally, it had a high potential for triggering allergic reactions.