What would be true for the structure labeled with letter ‘X’ in the given diagram showing the ultrastructure of Chlamydomanas?

1. It is the region of the chloroplast where circular DNA is present
2. It is associated with the operation of a carbon-concentrating mechanism (CCM)
3. It is the inclusion body with accumulated toxic wastes for elimination
4. It is filled with air and is responsible for buoyancy of the organism