____ we act now, more damage will be done. a- If b- Unless

Solution:

• The sentence states that 'more damage will be done' is the consequence of an action (or inaction). 'Unless' means 'if not'. So, 'Unless we act now' means 'If we do not act now'. This aligns with the consequence that more damage will be done if action is not taken.

Answer: b- Unless