Let's try eliminating the wrong answers:
Actors practice what they need to remember when they learn their lines, so that can't be what you're looking for.
The whole point of a mnemonic is to make things easier to remember, so that would also appear to be incorrect.
Any teacher can tell you that children learn better through 'doing', rather than 'listening', so that seems to eliminate the 3rd item in your list.
Which leaves only one!