Match List-I (Types of root apex organisation) with List-II (Arrangement of cells) and select the correct answer:

List-I	List-II
a. Type A	1. There are two sets of initials, one forming the central cylinder, the other forming the cortex and root cap
b. Type B	2. Meristems are differentiated into three tiers of initials, one forming the central cylinder, the second forming the cortex and the third the epidermis and the root cap
c. Type C	3. All parts of the root arise from a common initial region
d. Type D	4. All tissues are derived either from a single apical cell or from several initials arranged in one tier