A science teacher administered to a test after teaching the topic on Respiration and observed that majority of the students did not understand the difference between respiration and breathing. This could be due to the reason that (CTET Jan 2012)

• A. she could not explain the related concept effectively in the class
• B. she was not their class teacher
• C. the students could not understand the question correctly
• D. there was usually lot of indiscipline in her class