Please choose the correct ending to complete the given sentence: Finance and Business: [header] How to buy premium bonds [title] Decide if ns&i premium bonds are right for you. [step] Ns&i premium bonds are a savings account you can put money into and redeem at any time without penalty. Note that you cannot get withdraw your investment instantly like a bank account or isa.

Ending1: With these bonds, the interest you earn is based on a lottery system. Your bond number is put in a system that randomly draws a certain number of bonds per month one calendar month after purchase and will continue to be entered until you cash in your bonds. Ending2: [title] Determine if passive bonds are right for you. [step] Passive bonds are a small monthly deposit that you purchase only when you want to spend more of the investment. Ending3: In fact, you can only withdraw for an immediate period of time. [title] Check with the currently pending sale rates for premium bonds. Ending4: This is because you have to withdraw every month, whether you deduct from that a certain percentage of the investment or withdrawal a percentage of any difference. [substeps] There are zero-line premium bonds, because only about 3% of the investment is in your account.

Answer format: ending1/ending2/ending3/ending4