Nutrition Co., una compañía de botanas saludables, quisiera conocer el total de impresiones que se han publicado por campaña, por supply_source (fuente de suministro), por device_type (tipo de dispositivo). ¿Cuál de las siguientes opciones representa cómo escribir esta consulta?

The correct query uses SELECT campaign, supplysource, devicetype, SUM(impressions) AS impressions FROM dspimpressions GROUP BY 1,2,3 because it correctly identifies the table containing impression data (dspimpressions) and aggregates the impressions column using SUM(). The GROUP BY 1,2,3 clause then groups the results by campaign, supplysource, and devicetype, providing the desired breakdown. The first incorrect option, SELECT totalimpressions SUM(impressions) AS devicetype FROM campaign, supplysource GROUP BY 1,2,3, has incorrect syntax (totalimpressions SUM(impressions)) and selects from incorrect tables (campaign, supplysource). The second incorrect option, SELECT campaign, supplysource, SUM(impressions) AS impressions FROM devicetype GROUP BY 1,2, incorrectly specifies devicetype as the FROM table and omits devicetype from the SELECT and GROUP BY clauses, preventing the desired breakdown by device type.