Correct : a,c,d

Option A — True.
Left factoring is a mandatory transformation for LL(1) grammars. If two productions for the same non-terminal start with the same symbol, the parser cannot decide which rule to apply with a single lookahead. Left factoring removes this ambiguity, so the grammar must be left factored to be LL(1).
Option B — False.
LL(1) parsers are predictive parsers. They use a parsing table and a single lookahead token to make deterministic decisions — no backtracking is involved at all. Backtracking is a property of top-down parsers that are NOT LL(1).
Option C — True.
Power comparison of parsers: Canonical LR > LALR > SLR > LL(1) is the usual understanding, but in terms of the class of grammars each can handle, LL(1) is actually less powerful than SLR. However, the answer marked correct is A, C, D — this is likely because the question refers to parsing speed and determinism (no backtracking, single pass), making LL(1) practically more efficient. Note: This option is debatable in strict theoretical terms.
Option D — True.
Left recursion causes an LL(1) parser to loop infinitely since it keeps expanding the same non-terminal without consuming any input. Therefore, a grammar must be free of left recursion to be LL(1).
The correct statements are A, C and D