The question asks which code blocks return summary statistics for all columns in the DataFrame storesDF. The describe() method in Spark, when called without arguments (option E), computes count, mean, stddev, min, and max for all columns. Other options are incorrect: summary("mean") (A) returns only the mean, describe(all=True) (B) and describe("all") (C) use invalid parameters, and summary("all") (D) is invalid as "all" isn't a valid statistic. Thus, only option E is correct.