To evaluate a piece of media means to express the main idea in a clear and specific way.
disseminate the contents to a wide audience.
judge the purpose and message in a thoughtful way.
communicate the information to a group of people.

judge the purpose and message in a thoughtful way.

Explanation:

express the main idea in a clear and specific way – this is not the right answer. Evaluation is more complex and analytical than just the main idea.

disseminate the contents to a wide audience – this is not the right answer. Evaluation of the message doesn’t concern spreading it.

judge the purpose and message in a thoughtful way – this is the correct answer. Media is used to convey a certain message through some of the tools (radio, TV, internet, etc.) Therefore, its evaluation concerns seeing the message and analyzing it, giving the judge of it at the end. This includes possible critics or praise for the message, ways of conversion, tools, etc.

communicate the information to a group of people – this is an incorrect answer. Evaluation, as said before, does not concern the spreading of the information.

the answer should be b.

explanation:

it should be b because she researched before writing so it would be in past tense. "the author researches her subject before she had written the first draft.