(a) An advisory issued by the king to his subordinate

(b) A Dairy to be maintained for daily accounts

(c) A bill of exchange

(d) An order from the feudal lord to his subordinates

Answer: c

Explanation:

Sarafs (local Money lenders)  issued Hundis or Letters of authority or Bills of Exchange, in modern terminology.                                                                                                                                                                                   It enabled a person to transmit large sums of money from one place to another without any risk.                      He would deposit the amount, sometimes running into lakhs, with a saraf who would issue a hundi or letter of authority in the name of his agent which would enable the depositor to get his money within a specipied time at a place of his choice after paying some charges .

The English factors freely used this medium for sending money from one place to another.

Hence, option c is correct.

Read: Previous Year UPSC History Questions (PYQs) With Explanation 2020