A Physical Therapist Is Interested in Whether People with Different $\pm$

Multiple Choice

A physical therapist is interested in whether people with different bone structures will be affected differently by her new therapy program.She randomly chooses two groups of patients based on bone type: small-boned frame (X_S) and large-boned frame (X_L) .Patients all had similar injuries.She measures the number of days each person takes to progress to a predetermined point.Here is the data:
What are the critical values of t if the alpha level is .05?

A) $\pm$ 1.708
B) $\pm$ 2.052
C) $\pm$ 2.056
D) $\pm$ 2.060