Answer:
A. a primary source, because it is an excerpt of a radio address given by the president
Step-by-step explanation:
The above excerpt is actually "a primary source, because it is an excerpt of a radio address given by the president".
Primary sources are materials which have first-hand information. It gives a direct account of the person involved or an event the person carried out.
The "radio address" of the president is actually an original work which makes it a primary source because it gives direct account of the president's speech.
Examples of primary sources include: letters, speeches, records, autobiographies, manuscripts, etc.