- **Option 1: Alone, without assistance**: This phrase refers to doing something independently, without any help from others. It has no relation to the concept of force or control that "an iron hand" implies.

- ✅ **Option 2: Strict control**: The idiom "an iron hand" means to govern or manage with firmness and authority, often suggesting harshness or severity. This is the correct interpretation of the idiom.

- **Option 3: Memorising lessons**: This involves committing information to memory, typically through repetition. It doesn't align with the notion of controlling or managing situations or people.

- **Option 4: Straight talk**: This means speaking honestly and directly, without evasiveness. It does not capture the aspect of command or control that is central to the idiom "an iron hand".

YOUR ANSWER IS RIGHT