Answer:
Doctor, ace, connoisseur, virtuoso etc.
Explanation:
Synonyms are those words that have the same meaning with another word. They are different in all aspects, be it the spelling or the word or sound, but have a similar meaning with numerous other words. They all have the same connotation for a given word.
The word specialist means someone who is an expert in a specific field of study or issue or topic. So, its synonyms can be a <em>doctor,</em> a <em>consultant,</em> <em>virtuoso</em>, an <em>ace</em>, <em>professional</em>, <em>connoisseur </em>etc among others. They all signify someone who is an expert in a particular field of study. And considering there are n given options, the best answers can be among the numerous examples given in earlier.