are the most visible book industry segment, featuring hardbound and paperback books aimed at general readers and sold at bookstores and other retail outlets.

Trade Books.

Explanation:

Trade books can be defined as those books that are sold to the public fro reading by booksellers or retail sellers. It is different from the ones published by the textbook publisher's, or subscription books. The sole purpose of publishing trade books is for public or general readers. It is one of the most visible industry also.

Examples of trade publishers are Penguin, Macmillan, Harper Collins, etc.

Examples of trade books are fiction novel (romance, storybooks, etc), and non-fiction (biographies and autobiographies).

So, the correct answer is trade books.

nambe vazhkaile elam nala irukum

i think it's either 'to expose the corruption of the communists in russia', or 'to criticize animal brutality by communists in russia.'  

hope this ! : )