the barriers to wider ___________ of rooftop solar energy
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Adoption.
- 'Wider' is an adjective that requires a noun after it.
- 'Adopt' is a verb so it is eliminated.
- 'Adopting' is both a noun and a verb so it requires an object after it which is not provided in the passage.
- 'Adopter' is a noun but it describes a person while the passage needs a process.
- 'Adoption' is a noun and also a process.
Hence, the chosen option is correct.