What is the corrrect meaning of the word specialize

concentrate on and become expert in a particular subject or skill.

https://www.merriam-webster.com/dictionary/specialize#:~:text=Examples%20of%20specialize%20in%20a%20Sentence%20Some%20carpenters,who%20absolutely%20love%20getting%20people%20into%20active%20living.

Here's a link of some examples and the definition of the word specialize.

Explanation:

the sentence that avoid faulty coordination is:

culture, which is well represented in philadelphia, plays a major role including theatre, music, and the visual arts.  

faulty coordination occurs when the writer gives equal importance two different ideas (clauses) which in fact are not equivalent. in order to correct a misplaced clause or idea, the writer can place less important or emphatic ideas in a relative clause as in the previous sentence.