△ABC中，∠A+∠B=120°，∠C=∠A，则△ABC是[ ]

A.钝角三角形

B.等腰直角三角形

C.直角三角形

D.等边三角形

The speaker presents the passage by the following logic:
a. Induction.
b. Deduction.
c. Cause and Effect.
d. Comparison and Contrast.