In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No Error'.
Sorry to have(A)/troubled you; since(B)/it couldn't be helped.(C)/No error(D)
With whom did the Government of India sign a $ 120 million loan agreement to complete double-tracking and electrification of railway tracks along high-density corridors to improve the operational efficiency of India's railway network?