Triangles can be classified in terms of their angles and the length of their sides.
When we classify a triangle on the basis of its angles, one type of triangle is a right-angled triangle. In a right-angled triangle, one of the angles is exactly 90 degrees. In triangle XYZ, since angle Y is exactly 90 degrees, that makes the triangle a right-angled triangle.
Next, when we classify a triangle on the basis of the length of its sides, one type of triangle is an isosceles triangle. In an isosceles triangle, at least two sides are of equal length. In triangle XYZ, the sides XY and YZ are equal in length which makes this triangle an isosceles triangle.
Therefore, combining both qualifications, triangle XYZ can be classified in two ways: it is both a right-angled triangle (because it has one 90-degree angle) and an isosceles triangle (because it has two sides of equal length). Hence, the triangle XYZ falls under the (b) option - It is an Isosceles and right-angled triangle.