For a database relation $R(a, b, c, d)$ where the domains of a, b, c and d include only atomic values and only the following functional dependencies and those that can be inferred from them hold:
$a \rightarrow c$
$b \rightarrow d$
The relation is in ____
- First normal form but not in second normal form
- Second normal form but not in third normal form
- Third normal form
- BCNF