A young researcher set out to develop a method for quantifying the polycyclic aromatic hydrocarbon (PAH) content in a contaminated soil sample using open tubular gas chromatography. During the initial stages of method development, the researcher was unable to separate the early eluting compounds, anthracene and naphthalene, with baseline resolution. From the options below, select all possible modifications the researcher could make to improve the resolution. a. Use a column with a larger inner diameter
b. Use a column with a smaller inner diameter
c. Increase the column length
d. Decrease the column length
e. Decrease the temperature
f. Choose a different stationary phase
h. Increase the stationary phase thickness