Directions: Choose the option which is grammatically correct and the best version of the underlined part. A symbiotic relationship develops among the contractors, bureaucracy and the politicians and by a large number of devices costs are artificially escalated and black money generated through underhand deals.

and by a large number of devices costs are artificially escalated

and a large number of devices are used to escalate costs artificially

and costs are escalated artificially by a large number of devices

and they escalate the costs artificially using a large number of devices

and to escalate the costs, they have a large number of devices