Suppose that we have a relation schema R(A, B, C) representing a relationship between two entity sets with keys A and B, respectively and suppose that R has the FD: A $\rightarrow$ B, then the relationship in relational model possible is __________ .
A. One to many B. One to one
C. Many to one D. Many to many
if another key also mentioned than it will be one to one
According to their site