Answer:
Formal tone.
Explanation:
In literature, the tone is the way of speaking or attitude that the writer uses or takes. This way of expressing one's thoughts and the attitude used is known as the tone.
The given statement "One might wish to consider alternatives to television viewing" is a formal tone. A formal tone is where the speaker uses a serious attitude, and also denotes his/ her respect for the listeners, and includes no informal language such as slang or colloquialisms.