Q83a

Consider the context-free grammar $E \rightarrow E + E$ $E \rightarrow (E * E)$ $E \rightarrow id$ where $E$ is the starting symbol, the set of terminals is $\{id, (,+,),*\}$, and the set of nonterminals is $\{E\}$. Which of the following terminal strings has more than one parse tree when parsed according to the above grammar?