The correct answer is A. Informal
Step-by-step explanation:
The style of speech refers mainly to the way information is given during a speech and it is usually influenced by the audience and purpose of the speech. In this way, the style of speech changes the way the same information is delivered to different audiences and with purposes and the degree of formality of it. Some of these styles include formal style, casual style (informal) or consultative style (semi-formal). Thus, the word that describes a speech style is formal in which the language used is usually more complex than in other styles and little feedback from the audience as the relationship between the speaker and the audience is not a close relationship. Additionally, other options described mainly emotions, but not the way the information is delivered.