\item Let $\phi$ be a formula in CNF and $A$ an assignment of variables in $\phi$. Mark the following statements that are true. \begin{enumerate} \item[$\square$] A clause is \emph{satisfied} by $A$, if all variables are satisfied under $A$. \item[$\square$] If a clause is \textit{conflicting} under an assignment $A$, if all its variables are not satisfied under $A$. \item[$\square$] If a clause is \textit{conflicting} with an assignment $A$, all variables in the clause are given the opposite value in A. \item[$\square$] By the expression `$\phi[A]$' we denote that a variable within $\phi$ is satisfied under $A$. \end{enumerate}