Final answer:
Kylee must deposit her WorldMark credits at least 60 days in advance to ensure she has her accommodations secured and credits allocated properly.
Step-by-step explanation:
Kylee needs to deposit her week for WorldMark credits at least 60 days in advance from the start date. This is necessary to ensure that she can secure her preferred accommodation and have her credits properly allocated for her intended use. Depositing early maximizes the potential benefit of her WorldMark ownership and provides better vacation planning flexibility.