Answer:
Option C is the answer,until they they are able to give a perfect speech
Explanation:
Extemporaneous speech is a speech given with little or no preparation.
A speech that requires preparation but does not allow the speaker to read from their write-up is also known as impromptu or extemporaneous speech.
From my explanation above, it is crystal clear that option A is out of context since at some time point extemporaneous is not prepared well ahead, the same applies to option D.
In order to be able to deliver anytime , the speaker should prepare for a wide range of topics such that they can handle most topic areas by preparing until they are able to give perfect speech
