The pronoun 'les' is the best replacement for the direct object in the Spanish sentence provided.
Les would best replace the direct object in the sentence.
In the sentence 'Ellos llevaron las bolsas a la tienda,' 'las bolsas' is the direct object. When replaced with a pronoun, it becomes 'Ellos las llevaron a la tienda.'
Using the correct objective-case pronoun is essential to maintain grammatical accuracy.