Which Is True for Plate Height

Multiple Choice

Which is true for plate height?
I The smaller the plate height,the narrower the peaks.
II The larger the plate height,the better separation between peaks.
III Plate height can be calculated from the column length,L,and the number of theoretical plates,N.
IV For fixed number of theoretical plates,N,the longer a solute is on column,the wider the peak will become.

A) I,II,and IV
B) II and IV
C) I,III,and IV
D) II only
E) IV only