Option A is correct. Cortex Search Services can be integrated into a dimension's definition (using the field with 'service' and 'literal_column' fields) to improve literal matching by performing semantic search over the underlying column. This enhances Cortex Analyst's ability to find literal values for filtering, helping with 'fuzzy' searches. Option B is correct. The 'verified_queries' section allows pre- defining accurate SQL queries for specific natural language questions. Setting 'use_as_onboarding_ question true' for entries in the VQR ensures these queries are used when relevant and presented as suggested questions to users. Option C is incorrect; while metrics can reference logical columns, 'relationships' between logical tables are necessary for defining joins, especially across different underlying base tables. Option D is incorrect; 'custom_instructions' are provided at the model level to give general context to the LLM for SQL query generation, not embedded within individual dimension definitions. Option E is incorrect; the 'sample_valueS field is recommended for dimensions with relatively low-cardinality (approximately 1-10 distinct values) to aid in semantic search for literals, not for high-cardinality dimensions.