Which one among the following statements appropriately defines the term 'Drain Theory' as propounded by Dadabhai Naoroji in his work 'Poverty and Un-British Rule in India'? [NDA 2011-I]

• A. That a part of India's national wealth or total annual product was being exported to Britain for which India got no material returns
• B.  That the resources of India were being utilized in the interest of Britain
• C.  That the British industrialists were being given a opportunity to invest in India under the protection of the imperial power
• D.  That the British goods were being imported to India making the country poorer day by day