Which choice lists the following compounds in order of increasing solubility in water?
I. CH3–CH2–CH2–CH3 II. CH3–CH2–O–CH2–CH3 III. CH3–CH2–OH IV. CH3–OH
A. I < III < IV < II
B. I < II < IV < III
C. III < IV < II < I
D. I < II < III < IV