Answer:
•→ The motion of a particle or body in S.H.M acts towards a fixed point.
•→ Acceleration of the body under S.H.M is proportional to its displacement.
•→ This motion is periodic.
•→ Mechanical energy is conserved in S.H.M
Explanation:
S.H.M is Simple Harmonic Motion

The correct answer is the reverse wave I took the test
Answer A an Open Universe
The future of universe is predicted from space time curve. There are many possibilities solutions or outcomes which on plotting are classified as open, close, flat and curved. Open Universe is when universe is expanding and it will continue to expand forever. This is proved experimentally as well that universe is expanding using red and blue shift observations from various aspects.