Explanation

If you substitute the given numbers into the expressions in Quantities A and B, you can compare them.

Substituting in Quantity A gives \((r - s)^4\) = \((2 - (-7))^4\) = \(9^4\).
Substituting in Quantity B gives \(r^4 - s^4\) = \(2^4 - (-7)^4\) = \(2^4 - 7^4\).
Without further calculation, you see that Quantity A is positive and Quantity B is negative.

Now consider the possibility that r = s. In that case both quantity A ans Quantity B are equal to 0. hence right option is option D.

Thus the correct answer is Choice D.
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Sandy
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this is a classic case of substituting and finding out the value. But this can be solved using logic more efficiently

(r-s)^4 = (r2+s2)(r2-s2)
we have a r-s component which can simplify further, but rhs has a r+s. And we know nothing about r or s. Either can be any number of any sign.
Information Underload, so D..... booyah!