I will upvote, please answer fast

Middle aged women aged between 40-50 yrs old residing in Nilai with chronic back pain for 2 years or more were asked to participate in physiotherapy treatment at INTI Physiotherapy clinic. Those who consented to the treatment were randomly assigned into a control group (consultation and conventional treatment X) and treatment group (consultation and innovative treatment Y ). The treatment session was given to both groups for the period of 2 months. At the end of 2-month treatment, women were asked to participate in the same questionnaires to assess the effectiveness of physiotherapy treatment Identify and explain any ONE (1) control variables of the above scenario