Gabe is taller than Helen, Helen is shorter than Iris. Iris is shorter than both jack and Keiko. Which of the following statement is true?

AThe tallest person must be Gabe.
BThe tallest person must be Jack.
CThe tallest person must be Keiko.
DEither Jack or Keiko must be the tallest person
EGabe, Jack, or Keiko could be the tallest person