The correct answer is B. alternate interior angles. Both angles are on the inside of the two parallel lines, making them interior angles, and they are alternate because they're not on the same sides of the transversal line (the line that cuts through the parallel lines). A is incorrect because corresponding angles are those that are in the same position on both parallel lines, C is incorrect because it's impossible to tell with the information given if the angles are obtuse, and D is incorrect because adjacent angles are those that are next to each other.