onsider the following two services:book publishing and magazine publishing. We will say that economies of scope exist between he two services if

A$.$ the cost of publishing a magazine is lower for book publishers than for other firms.

B$.$ the cost of publishing a magazine is lower for firms that publish many magazines than for firms that publish only one magazine.

C$.$ the cost of publishing a book falls over time as the publisher acquires more experience.

D$.$ the cost of publishing a book is not subject to diminishing marginal returns.

E$.$ All the above.