Hello native English speakers. Thank you in advance for solving my queries which are based on 3 sentences. 1a. Flood and guerrilla forces ravaged the area.→ 1b. The area was ravaged by flood and by guerrilla forces. 1c. The area was ravaged by flood and guerrilla forces. 2a. We must handle radiation sources with great care and by remote control. 2b. Radiation sources must be handled with great care and by remote control. 2c. Radiation sources must be handled by us with great care and by remote control. 2d. Radiation sources must be handled with great care and by remote control by us. 2e. Radiation sources must be handled by us with great care , by remote control. 3a. I was very irritated by the man in the blue suit. 3b. I was irritated by the man in the blue suit. Question: Which is grammatically correct?