In an economic evaluation, the alternatives must be well specified. What do we mean by this? Select one: O a. That the authors can always omit the do-nothing or "no treatment" option. O b. That each alternative under comparison must be specified in detail, and the omission of alternatives that might be relevant must be justified. O c. That the authors must enumerate the alternatives under comparison. O d. That each alternative under comparison must be specified in detail, but it is not necessary to justify the omission of alternatives that might be relevant. Suppose