A typical Bayesian network, showing both the topology and the conditional probability tables $($CPTs$).$ In the CPTs$,$the letters B$,$ E$,$ A$,$ J$,$ and M stand for Burglary, Earthquake, Alarm, JohnCalls, and MaryCalls, respectively.$$If no evidence is observed, are Burglary and Earthquake independent?$$a$)(6$pt$)$ Prove this using the definition $($i$.$e$.,$ definition of independence: P$($X$,$ Y$)=$ P$($X$)$P$($Y$)),$similar to we showed in class.