Terrorists are trying to__________ several bridges.

Correct option is A

"Blow up" refers to the act of destroying something using explosives, making it the correct answer in the context of terrorists targeting bridges. "Breakdown" and "fallout" have different meanings and do not fit the context.
Information Booster:
1. "Blow up" is a phrasal verb meaning to destroy violently.
2. "Breakdown" refers to a failure or malfunction.
3. "Fallout" relates to consequences or radioactive particles.
4. Correct usage of phrasal verbs is crucial for clarity in communication.