What Is the Purpose of the Stardust Space Probe

What is the purpose of the Stardust space probe?

A) to plunge into the nucleus of a comet, throwing dust and icy grains out from under the comet''s surface into space, where they can be seen and analyzed from the EarthEarth
B) to analyze dust samples from other stars and transmit the results back to the EarthEarth
C) to fly through the tail of a comet and transmit images back to the EarthEarth
D) to collect samples of comet material and bring them back to the EarthEarth