What is an angle which is less than 180 degrees but more than 90 degrees called?

The correct option is B Obtuse angle

$\begin{array}{cc}\text{Type of angle}& \text{Description}\\ \text{Acute angle}& \text{Less than}{90}^{\circ }\\ \text{Right angle}& \text{Equal to}{90}^{\circ }\\ \text{Obtuse angle}& \text{Greater than}{90}^{\circ }\\ & \text{\& less than}{180}^{\circ }\\ \text{Straight angle}& \text{Equal to}{180}^{\circ }\end{array}$

Thus, an angle that measures less than ${180}^{\circ }$ and greater than ${90}^{\circ }$ is called an obtuse angle.