Geometry

Question Analysis:
This question involves basic properties of isosceles triangles.
The main focus is on understanding the relationship between equal sides and equal angles in an isosceles triangle.

Key Concept Explanation:
An isosceles triangle has at least two equal sides.
The angles opposite these equal sides are always equal.
This is a fundamental property of isosceles triangles.

Step-by-Step Solution:
Given that XY = XZ, we know that △XYZ is isosceles with XY and XZ as the two equal sides.
In any isosceles triangle, the angles opposite the equal sides are equal.
Since XY = XZ, the angles opposite these sides are ∠Y and ∠Z, meaning ∠Y = ∠Z.
Therefore, the correct answer is A) ∠Y = ∠Z.

Option Analysis:
A) Correct. The base angles of an isosceles triangle are always equal.
B) Incorrect. XY = XZ, but this does not imply XY = YZ.
C) Incorrect. XZ = YZ would mean the triangle is equilateral, which is not necessarily true.
D) Incorrect...