Read the passage and select the most appropriate option for the specified blank. The Amazon Rainforest, often referred to as the “lungs of the Earth,” (1)________ 20% of the world's oxygen. It is home to a wealth of biodiversity, (2)__________ many species found nowhere else on the planet. Unfortunately, deforestation has become a (3)_________ problem, leading to the loss of habitat and (4)___________ the carbon cycle. Conservation efforts are crucial to (5)_________ the rainforest's health and longevity. Select the most appropriate option for blank 2.

1. includes
2. include
3. included
4. including