'What does that say' challenges you on homographs.
As you will have been discovering, English has a rich range of words that look the same but can sound differently, and/or carry very different meanings, according to their context. How good are you at distinguishing between members of these pairs, or even larger groups?
In Answer 2 the word is a straightforward noun; its metaphorical meaning appears in the verb in Answer 3 ( = 'to move backwards; to withdraw'), but ~ perhaps confusingly ~ we can also 'back' something when we are supporting it (as in the 'I'm backing Britain' campaign, back [!] in the 1960s, to encourage people to buy British-made products and support the economy, such as the original Mini car).
'Back' in Answer 4 means the rearmost, e.g. the back seat in a bus or cinema. The metaphor here aims to suggest that the new-year plans do not require active attention in the imminent future ~ like putting a pan on to simmer gently at the back of the stove, while you are busier stirring something else nearer to you.