Explanation:
The sum of the angles of a triangle is always 180°. Using this property, we can easily find the value of xab, xbc, and xca.

Let's consider the triangle ABC:

Angle BAC = xca
Angle ABC = xbc
Angle BCA = xab

Using the property that the sum of the angles of a triangle is 180°, we get:

xab + xbc + xca = 180°

Therefore, the sum of the angles xab, xbc, and xca is equal to 180°.

But we know that xab, xbc, and xca are angles of a triangle. The sum of the angles of a triangle is also 180°. Therefore, we can conclude that:

x + x + x = 180°

Simplifying the above equation, we get:

3x = 180°

Dividing both sides by 3, we get:

x = 60°

Now, we can substitute the value of x in the equation xab + xbc + xca = 180°:

xab + xbc + xca = 180°

60° + 60° + 60° = 180°

Therefore, xab, xbc, and xca are all equal to 60°.

Now, we can calculate the value of xab * xbc * xca:

xab * xbc * xca = 60° * 60° * 60°

xab * xbc * xca = 216,000°

Since 216,000° is not equal to 1 or 0, the correct answer is option 'D' - none of these.

Therefore, the correct answer to the given question is option 'D' - none of these.

X^a-b+b-c+c-a x^a-a+b-b+c-c x^0 =1