Both written texts and spoken presentations should

Generally, however, like the written presentation, oral presentations have distinct parts  an introduction, a main body, and a conclusion. The introduction should clearly tell the audience what the presentation will cover so that the audience is prepared for what is to come.

Should be the clearest posible

Explanation:Dear student, generally when you are writting texts you must be clear in both your grammar and spelling, as well avoid using short forms of the English independently of the dialect.

When you are making spoken presentations, take your time to prepare your presentation and get ready when you present it. The are ways to help this like practicing in front of a mirror, talking with a friend requesting them to correct you if you miss something, and last but not least have faith in yourself.

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.