Answer:
C. Because materials developed for use in space are often useful to ordinary citizens.
Step-by-step explanation:
A, is not correct due to the "only" word. Humans can explore space too.
B, not that either because you will need lots of technology to space travel, not less.
C, because materials that can be produced through scientists' ideas can help contribute to society and improve technology.
D, is not correct because there is no need for new materials for new technology.