INCORRECT. Almost correct. Ostensibly nothing happens, because we don't get a signal back from the rest of the patient.
CORRECT. During slice selection, the slice selection gradient acts on the whole length of the scanner bore. This means that the Larmor frequencies of hydrogen protons vary from one end bore to the other. This allows us to choose a particular section to excite (rotate magnetisations into the xy-plane) by using an oscillating magnetic fields of certain frequencies (an RF pulse with a certain bandwidth).
INCORRECT. Rotation of magnetisation by the RF excitation pulse is exactly what doesn't happen in the rest of the patient.