Task: Question Answering
Input (English): Problem: an engineer undertakes a project to build a road 15 km long in 300 days and employs 50 men for the purpose . after 100 days , he finds only 2.5 km of the road has been completed . find the ( approximate ) number of extra men he must employ to finish the work in time . 
Options: a ) a . 43 , b ) b . 45 , c ) c . 75 , d ) d . 68 , e ) e . 60
Output (English): c