Create a DataFrame called clean_taxi that only includes trips with a positive passenger count, a positive distance, a duration of at least 1 minute and at most 1 hour, and an average speed of at most 100 miles per hour. Inequalities should not be strict (e. g., <= instead of <) unless comparing to 0. The provided tests check that you have constructed clean_taxi correctly.

Which best describes the role or restriction enzymes in the analysis of edna a. to break dna into fragments that vary in size so they can be sorted and analyzed b. to amplify small amounts of dna and generate large amounts of dna for analysis c. to purify samples of dna obtained from the environment so they can be analyzed d. to sort different sizes of dna fragments into a banding pattern that can be analyzed