The correct answer is the option c. be read in several different ways. In his essay "Of studies (1625)" Francis Bacon talks about different ways in which a book should be read. This is an excerpt from the essay that will illustrate the point:
<em> " Some books are to be tasted, others to be swallowed, and some few to be chewed and digested; that is, some books are to be read only in parts; others to be read, but not curiously; and some few to be read wholly, and with diligence and attention. Some books also may be read by deputy, and extracts made of them by others; but that would be only in the less important arguments, and the meaner sort of books, else distilled books are like common distilled waters, flashy things." (Bacon, 1625)</em>
In other words, there's a lot of books out there, as a reader you may encounter good books, some difficult to read because of technicism and some boring ones. It's not the option <em>a. be read only by adults</em> as he doesn't talk about adults or children, he talks about "man" to be wise and read wisely in general.
It's not the option <em>b.be read only by scholars</em> as Bacon thinks all men can look at different pieces of literature and approach to them differently and that will make an interesting point of view, as scholars will tend to have different thoughts regarding their specialty, simple man will look at them superficially and wise men will appreciate what they read not just for the content, they will go further.
And finally, it's not the option <em>d. always be read in their entirety</em> because as Bacon said "Some books are to be tasted, others to be swallowed..." he is not talking about reading their entirety but to get the best of every book or read it in a different way so you approach will be different.
