Claudio is conducting a study on mindfulness meditation. One group in his study is instructed to practice meditating for 30 minutes per day and the other group is asked to take a 30-minute walk each day while listening to their favorite music. He decides to give a mindfulness inventory questionnaire to his participants to check if the meditation group actually demonstrated mindfulness. This practice is known as _________.a) variable check
b) manipulation check
c) validity check
d) debriefing
