Scientists Have Now Examined Rocks That Came from Mars in Their

Scientists have now examined rocks that came from Mars in their laboratories on Earth because:

A) an orbiting spacecraft scooped up Martian dust during its passage by Mars and then returned to Earth.
B) several meteorites found in Antarctica are now thought to have been knocked off Mars and fallen to Earth.
C) spacecraft have been to the surface of Mars and have returned with samples of Martian rocks and soil.
D) a large impact that occurred on the Martian surface early in its history created a vast dust cloud through which Earth passes once per year, and samples of this dust have now been collected by the Space Shuttle.