This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to substitute for mustard seed
Use prepared horseradish to add spice.
Prepared horseradish is made by combining ground horseradish with vinegar, and sometimes other spices, to form a sauce. You can get it from your local supermarket.

Choices:
(A). The consistency of this sauce can be thickened to your taste. For even better flavor use wheatgrass, which is more spicy but still better when seasoned.;
(B). Cook the horseradish for 30 minutes. Place the pan on the stove and turn it on to high.;
(C). Pinch off a clove of garlic. Whole cloves of garlic are raw and most may be kind of bitter.;
(D). In place of mustard seed, use the same amount of prepared horseradish to add spice and complexity to your recipe. Add mayonnaise to achieve the same consistency.;
The answer is:
(D).