Answer: b. birds have beaks adapted to break open hard shells
Step-by-step explanation:
The birds in the tropical rainforests are adapted to have sharp and long beaks. This helps these birds to eat fruits, insects, small lizards, unhatched eggs. Moreover,the long beak allows them to grab fruits from the tree tops and to break open the shells and nuts. This allows these birds to grab a variety of food items and also helps them to survive in conditions in scarcity of foods by eating hard nuts and shells.