Q66

Consider the following snapshot of a system running $n$ processes. Process $i$ is holding $x_i$ instances of a resource $R$, $1\leq i\leq n$ . Currently, all instances of $R$ are occupied. Further, for all $i$, process $i$ has placed a request for an additional $y_i$ instances while holding the $x_i$ instances it already has. There are exactly two processes $p$ and $q$ and such that $y_p=y_q=0$. Which one of the following can serve as a necessary condition to guarantee that the system is not approaching a deadlock?