$300 000 to invest, 75 yr old couple

My inlaws have sold their property and live in long term care. The bank is trying to sell them mutual funds consisting of private bonds (mostly bank bonds).

They want to put the $300k somewhere secure and make at least inflation.

GICs are 3%. The CIBC advisor is saying the mutual fund will get them 5%. (Though I didn't think a mutual fund provided a guaranteed return like that-I wasn't at the meeting.)

They maxed out their TFSA in a high interest account.

I know a fair bit about equity etf, but not that much about fixed income etf.

I would think they would be better off putting it into ETF like CLF (govt bonds), though interest/payout has been about 2.2%.

Any fixed income suggestions?