Which would be losing its seeds pterphyta angiosperms gymnosperms

First of all, pterophyta have neither seeds nor flowers in the first place.. Angiosperms are flowers and are the most diverse group of land plants so I doubt they would be losing its seeds... Lastly gymnosperms are a group of seed producing plants.. According to what I just wrote, what do you think the answer is??

The answer would be sand and gravel