The correct answer is ( A )
This article is about an invention called ReWalk uses robotic pants with sensors and motors to allow people in wheelchairs to walk. The other statements (B), (C) and (D) are secondary ideas which expand the main concept or thesis statement.
I'd go with A because the other options don't make sense at all.
Answer:
They introduce a problem that 3-D printers could help solve.
Explanation:
I got right
PC stands for Personal Computer
