In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Question: How many people were killed at the battle in the Wyoming Valley where Hartley's Regiment would arrived later? Passage:On 8 January 1778, Hartley's Regiment was assigned to the Middle Department and in March it became part of the Pennsylvania Line. Captain William Scott's company from Thruston's Additional Continental Regiment was absorbed on 4 April 1778. Sent to the Pennsylvania frontier to oppose raids by the Iroquois and their American Loyalist allies, Hartley's Regiment arrived in the Wyoming Valley after the Wyoming Massacre. In September 1778, elements of the regiment participated in a counter-raid in which they destroyed a few Indian villages, recovered plunder taken in the Wyoming Valley, and skirmished with the Native American warriors. Hearing that a large body of Indians was assembling at Unadilla, Colonel Hartley withdrew his 130-man column. On 13 January 1779, following a resolution of the Continental Congress Hartley's Regiment was consolidated with Patton's Additional Continental Regiment and the three companies of Malcolm's Additional Continental Regiment commanded by Captains John Doyle, John Steele, and James Calderwood and were ordered to join the Pennsylvania Line. The new unit was named the 11th Pennsylvania Regiment and organized in the strength of nine companies. Colonel Hartley, officially resigned his commission a month later on February 13, 1779.
Links: a. Unadilla, New York b. Patton's Additional Continental Regiment c. Iroquois d. Battle of Wyoming
d