Task: Class Definition Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes 'C-X-C motif chemokine 12 receptor activity'?

A. Any process that decreases the frequency, rate or extent of division septum formation. division septum formation is he assembly and arrangement of a septum that spans the plasma membrane interface between progeny cells following cytokinesis.
B. Combining with the C-X-C motif chemokine 12 (CXCL12) and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity.
C. Combining with interleukin-8 and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity.
D. The directed movement of guanine, 2-amino-6-hydroxypurine, into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore.

Answer: Combining with the C-X-C motif chemokine 12 (CXCL12) and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity.