Question

Suppose you need to stock a heavy item on a shelf, but are not sure you can lift it. You are the only one stocking in the store.

Answer 1

2. Tell the manager you cannot stock the item 
I´m not sure really, the first three are good options  

For the second question I would choose:
2. Ask the manager if you can get off early, but do not mention that you might be sick.
I mean after all you are well enough to work so it doesn´t really matter at the time

Answer 2

The last one because there is no one else in the store so it's only u and u can just make ur life easier.