The logic here is confusing to me, maybe do something like:
```python
for bmass, option_name in [('N', 'No'), ('Y', 'Yes'), ('Unknown', 'Unknown')]:
    selected = 'selected' if bmass == biomass_remaining else ''
    req.write("<option value='{0}' {1}>{2}</option".format(bmass, selected, option_name))
#END Indent
```