[单选题]
The photomicrograph bep/ .zg3w-o ;rkuzrw8 ylow shows uv3y 9pvspy6. a root tip meristem. Which of the following sentences correctly defineu 3spv6vpyy9.s a meristem?
A. A region of a plant with differentiated cells that undergo cell division
B. A region of a plant with undifferentiated cells that undergo cell division
C. A region of a flower that undergoes cell division
D. A region of a plant where cell differentiation occurs in response to a change in day length
