Triple

Given a phrase, classify it is english named entity (e.g., persons, organizations, works of art) in Latin script, or not (e.g., literals, dates, URLs, verbose phrases). For disambiguation, the statement where the phrase occurs as object is also given. Please return a JSON object with `phrase` (string, the phrase being analyzed) and `is_ne` (boolean, indicating whether the phrase is a Named Entity).

Phrase: Columbia River mainstem | Statement: [Duncan Dam reservoir, isUpstreamOf, Columbia River mainstem]

Target entity: Columbia River mainstem
Context triple: [Duncan Dam reservoir, isUpstreamOf, Columbia River mainstem]

• A. Columbia River chosen
  The Columbia River is a major river of the Pacific Northwest that forms much of the border between Oregon and Washington and is vital for hydroelectric power, transportation, and regional ecosystems.
• B. Columbia River Basin
  The Columbia River Basin is a vast watershed in the Pacific Northwest that drains portions of seven U.S. states and British Columbia into the Columbia River, supporting major ecosystems, agriculture, and hydroelectric power.
• C. Lewis and Clark River
  The Lewis and Clark River is a small coastal river in northwestern Oregon that flows through forested terrain into the Youngs River near Astoria, historically associated with the Lewis and Clark Expedition.
• D. Jefferson River
  The Jefferson River is a major tributary of the Missouri River in southwestern Montana, known for its scenic valleys, trout fishing, and role in the Lewis and Clark Expedition.
• E. The Dalles–Celilo reach of the Columbia River
  The Dalles–Celilo reach of the Columbia River is a historically and culturally significant stretch of the river in the Pacific Northwest, once renowned for its powerful rapids and rich Indigenous fishing sites before being largely submerged by dam construction.
• F. None of above.
• G. Unsure - the case is ambiguous/there is not enough information to decide.