1) When I put the data for my response spectrum, it says that value of frequency should be increasing. Dooes it mean that I should invert the order of values of frequency as well as corresponding spectral acceleration?

2) 2nd question is that which option should i use to put my data in abaqus?

1) Displacemnt

2) Acceleraton

3) Velocity

4) Gravity

I am confused between acceleration and gravity?

Any help would be highly appreciated.