What RRA to select if the polling interval is 120 mins

[liquorice]

I have created a perl script to measure the download speed from internet. And I am downloading a 12M file. I intend to do this every 2 hours (step: 7200 secs, heartbear: 14400) but I am not sure what RRAs i should select. Do I select "Daily (5 mins), Weekly (30 mins), Monthly (2 hours) and Yearly (1 day)" or "Weekly (30 mins), Monthly (2 hours) and Yearly (1 day)" ?