Final answer:
Tisquantum, known as Squanto, was a member of the Patuxet tribe who acted as a translator and advisor between the Pilgrims and the Wampanoag Confederacy, facilitating a treaty that lasted for two decades.
Step-by-step explanation:
Tisquantum, more commonly known as Squanto, acted as an interpreter and advisor to the Pilgrims who arrived on the Mayflower. Squanto was a member of the Patuxet tribe which was part of the Wampanoag Confederacy. He played a critical role in the survival of the early settlers by teaching them local agricultural methods and serving as a translator in critical negotiations between the Pilgrims and the Wampanoag leader, Massasoit. Notably, Squanto's efforts led to a treaty in 1621 between the Pilgrims and the Wampanoag, which lasted for 24 years.
Thus, the answer to the student's question is (d) He acted as translator between Ousamequin (Massasoit) and the Pilgrims. Tisquantum did not guide the Mayflower (eliminating option a), did not lead the Native people in King Philip's War (eliminating option b), and was not a sachem (eliminating option c).