Which of the Following Reactions Is Catalyzed by a Transketolase

Which of the following reactions is catalyzed by a transketolase in the pentose phosphate pathway?
I.
Fructose-6-P + glyceraldehyde-3-P ⇔ xylulose-5-P + erythrose-4-P
II.
Erythrose-4-P + fructose-6-P ⇔ sedoheptulose-7-P + glyceraldehyde-3-P
III.
Sedoheptulose-7-P + glyceraldehyde-3-P ⇔ ribose-5-P + xyulose-5-P

A) I only
B) II and III
C) II only
D) I and III
E) I and II