Why is the neighbor relationship between R1 & R2 and R1 & R3 an L2-type neighborship?

Refer to the exhibit.

Why is the neighbor relationship between R1 & R2 and R1 & R3 an L2-type neighborship?

A.
because the area ID on R1 is different as compared to the area ID of R2 and R3

B.
because the circuit type on those three routers is L1/L2

C.
because the network type between R1, R2, and R3 is point-to-point

D.
because the hello interval is not the same on those three routers