複選題

7. Based on the low-resolution proton NMR spectrum of a particular compound shown at the right, which of the following is(are) true? (2 pts)
 I. There are at least three different types of protons in this compound.
 Il. There are more protons of the type cotresponding to peak 3 than the type corresponding to peak 1. III. Protons of the type corresponding to peak 2 are more
 shielded than those corresponding to peak l.
  
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) I, II, and III.