The Future of Space Travel May Not Lie with Humans

The future of space travel may not lie with humans, but with robots. At the dawn of the space age, space travel required human astronauts-they were simply more capable than robots. But humans developed technology that steadily made robots more attractive. Astronauts have to breathe, eat, and drink to keep going. But robots can travel to the ends of the solar system free of such constraints. They can do more, go further, and because they don't require costly life-support systems, they can do it all more often. Of course, they still require human direction. Nevertheless, we should all look for more robotic space travelers in the future.
Below are several topics being discussed in the media. Which of the following resembles the theme of the passage on robotic space travel?

A) The percentage of people traveling abroad is at an all-time high.
B) The latest issue of Book Review contains a special report about robots in fiction.
C) A remote-controlled deep-sea submersible has mapped the deepest sections of the Pacific Ocean.
D) Students are graduating from college with degrees in robotics in record numbers this year.