Let $A$ and $B$ be two events such that $P(\overline{A \cup B})=\frac{1}{6}, P(\overline{A \cap B})=\frac{1}{4}$ and $P(\bar{A})=\frac{1}{4}$, where $\bar{A}$ stands for the complement of the event $\mathrm{A}$. Then the events $\mathrm{A}$ and $\mathrm{B}$ are [Main 2014]
(a) independent but not equally likely.
(b) independent and equally likely.
(c) mutually exclusive and independent.
(d) equally likely but not independent.