The correct answer is OPTION 2 -Flock

The most fitting collective noun for birds is: Flock

• Fleet is typically used for ships or vehicles.
• Mob is used for a disorderly or unruly crowd, not birds.
• Crowd is a general term for a large group and doesn't specifically apply to birds.
• Flock is the most common collective noun for a group of birds, signifying them flying or feeding together.