What does Lexicology, a brunch of linguistics study?

There are three types of synonyms: ideographic, stylistic and absolute. What is a stylistic type?

1. 
   It differs in shades of meaning.
   
2. 
   It differs in stylistic characteristics.
   
3. 
   It coincides in all their shades of meaning.
   
4. 
   It has the same concept but differs in meaning.
   
5. 
   It has the same stylistic characteristics.
   

17. 
    Can we define the language spoken in the USA as an American language?
    

1. 
   We define it as an American language.
   
2. 
   We define it as one of the dialects of the English language.
   
3. 
   We define it as an independent language.
   
4. 
   We define it as a different kind of the English language.
   
5. 
   We define it as a regional variety of the English language.
   

17. 
    To which parts of speech do most antonyms belong?
    

1. 
   They mostly belong to verbs.
   
2. 
   They mostly belong to nouns.
   
3. 
   They mostly belong to adverbs.
   
4. 
   They mostly belong to adj ectives.
   
5. 
   They mostly belong to verbs and nouns.
   

17. 
    What is the general tendency with the English vocabulary at the modem stage of its history?
    

1. 
   To increase the total number of its meanings.
   
2. 
   To involve the appearance of its new meanings.
   
3. 
   To develop the semantic structure of a word.
   
4. 
   To narrow the total number of its meanings.
   
5. 
   To add new words to the English vocabulary.
   

17.