The mole is a nocturnal insectivorous mammal regarded as pests by gardeners because of their burrowing activity spoiling lawns and gardens.

• A. regarded as pests by gardeners because of their burrowing activity spoiling
• B. regarded to be pests by gardeners because of their burrowing activity's spoiling
• C. regarded as a pest by gardeners because its burrowing activity spoils lawns and gardens
• D. considered as a pest by gardeners because of its burrowing activity spoiling