考虑左递归文法S->Aa|b A->Ac|Sd|e,消除左递归后应该为( )? S->Aa|b A->bdA’|A’ A'->cA’|adA’|e S->Ab|a A->bdA’|A’ A’->cA’|adA’|e S->Aa|b A->cdA’|A’ A’->bA’|adA’|e S->Aa|b A->bdA’|A’ A’->caA’|dA’|e
S->Aa|b A->bdA’|A’ A'->cA’|adA’|e
S->Ab|a A->bdA’|A’ A’->cA’|adA’|e
S->Aa|b A->cdA’|A’ A’->bA’|adA’|e
S->Aa|b A->bdA’|A’ A’->caA’|dA’|e