"Professional" is one word that could fit this blank.
        
                    
             
        
        
        
Answer: A. a poetic foot made up of an unstressed syllable followed by a stressed syllable.
Explanation: In poetry, an iamb is a foot or beat consisting of an unstressed syllable followed by a stressed syllable, or a short syllable followed by a long syllable, iambic foots were used in traditional traditional English poetry and verse drama. So, according to this information, the correct answer is the definition given by option A:  a poetic foot made up of an unstressed syllable followed by a stressed syllable.
 
        
                    
             
        
        
        
Idiom is an expression particular to a region