A researcher has developed a new drug designed to reduce blood pressure In an experiment 21 subjects wer assigned randomly to the treatment group and received the new experimental drug The other 23 subjects were assigned to the control group and received a standard well known treatment After a suitable period the reduction in blood pressure for each subject was recorded A summary of these data is n x S Treatment group new drug Control group old drug 21 23 23 48 18 52 8 01 7 15 Without using software how would you estimate the number of degrees of freedom for this problem O A Use the smaller value 21 chosen from the two options 21 and 23 O B Use the larger value 23 chosen from the two options 21 and 23 O C Use the smaller value 20 chosen from the two options 20 and 22 D Use the larger value 22 chosen from the two options 20 and 22