[单选题]
The photomicrograph below shows a 2t:lo6jydd ,xisj d;; root tip meristem.k5cdb, w6 un7h Which of the following sent, wc76bhd5n kuences correctly defines 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
