Answer:
I would rollover.
Step-by-step explanation:
It is expected an increase in the interest rate in the near future. It is better to wait for the purchase of a long-term note because, once the interest rises, the price of the TS at 9 years will decrease to match the new yield.
While doing a rollover we can make the cash work at 5% and start yielding at 7% in six month. Once the expectation of higher interest rate vanish, I can consider moving to a long Treasury Bill, which most probably will have a lower cost than today.