CREATE TABLE table_28853064_15 (stage VARCHAR(255), winner VARCHAR(255), team_classification VARCHAR(255), mountains_classification VARCHAR(255))
In what stage did Jaime Vergara won, Team Classification was given to EPM-Une and Mountain Classification winner was Oscar Solis?
    
SQL: SELECT stage FROM table_28853064_15 WHERE team_classification = "EPM-UNE" AND mountains_classification = "Oscar Solis" AND winner = "Jaime Vergara"