A double-blind study was conducted to study the effectiveness and safety of the drug temazepam as a treatment for insomnia. 55 patients with diagnosed insomnia were randomly assigned to take one of two pills at bedtime: 26 patients took a placebo for 4 consecutive nights, 29 patients took 30 mg of temazepam for 4 consecutive nights. All patients completed sleep questionnaires following the 4th night. Which of these kinds of biases could not have occurred in this study? Question 5Select one: a. Sufferers may experience different symptoms and/or severity of insomnia. b. Inexperience with a sleep product before the study took place could bias the volunteer responses. c. Patients could have altered their sleep patterns since they were aware that they were part of a study. d. The questionnaire could have been designed using leading questions. e. Some patients could have lied on the questionnaire