Final answer:
The correct answer is A. The type of reaction where Element A + compound B produces Element C + compound D is a single replacement reaction, characterized by one element replacing a similar element in a compound.
Step-by-step explanation:
The reaction type described in the equation Element A + compound B → element C + compound D is a single replacement reaction. A single replacement reaction, also known as a single-displacement reaction, occurs when one element (A) replaces a similar element (B) in a compound, resulting in the formation of a new compound (AC) and releasing the replaced element (B).
In the general form of such reactions, for metals replacing metals, the equation takes the form A + BC → AC + B. If nonmetals are involved, a nonmetal will replace another nonmetal in a compound. It is important to note that for a single replacement reaction to occur, the replacing element must be more reactive than the element it replaces. This is often determined with the help of a reactivity series or activity series, which lists elements according to their reactivity.