Suppose That a Firm Produces Both Steel and Electricity

Suppose that a firm produces both steel and electricity.It is cheaper for this firm to produce both goods than it would be if they were produced by two separate firms.Further,as this firm increases its production levels of both products,the average cost of producing steel rises,while the average cost of producing electricity remains constant.This firm experiences:

A) economies of scope, diseconomies of scale in the production of steel and constant returns to scale in the production of electricity.
B) economies of scope, economies of scale in the production of steel and constant returns to scale in the production of electricity.
C) diseconomies of scope, economies of scale in the production of steel and constant returns to scale in the production of electricity.
D) diseconomies of scope, diseconomies of scale in the production of steel and increasing returns to scale in the production of electricity.