The $pK_a$ of acetylsalicylic acid (aspirin) is $3.5$. If the $pH$ of human stomach fluid is $2-3$ and the $pH$ of the small intestine fluid is $8$,then aspirin will:

• A
  not ionize in the small intestine and the stomach.
• B
  completely ionize in the small intestine and the stomach.
• C
  ionize in the stomach and not in the small intestine.
• D
  ionize in the small intestine and not in the stomach.