Correct Answer:
B. every two years
Biennial means occurring every two years.
- Correct answer - every two years: it has the same meaning as Biennial.
- favourable: helpful or approving - wrong, it does not mean the same as Biennial.
- yearly: once every year - wrong, it does not mean the same as Biennial.
- impressive: making a strong good impression - wrong, it does not mean the same as Biennial.