Please answer a question about the following article about New Delhi:

Connaught Place, one of North India's largest commercial and financial centres, is located in the northern part of New Delhi. Adjoining areas such as Barakhamba Road, ITO are also major commercial centres. Government and quasi government sector was the primary employer in New Delhi. The city's service sector has expanded due in part to the large skilled English-speaking workforce that has attracted many multinational companies. Key service industries include information technology, telecommunications, hotels, banking, media and tourism.

New Delhi's service sector has expanded largely due to skilled workers that speak what language?
English