In the following passage, some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each blank.

Comprehension:
Tourism is one (1)______ the biggest businesses in the world, generating (2)______ 200 million jobs. It is vital for the economies of (3)______ countries. The downside is that tourism is a major (4)______ of climate change through the carbon (5)______ it causes.