Final answer:
The term 'Extended' is not a recognized type of chemical reaction, making it the correct answer to the student's question. It does not describe a specific reaction mechanism like single replacement, combustion, or decomposition.
Step-by-step explanation:
The student's question asks to identify which of the provided options is not a type of chemical reaction. The options to consider are: a) Single replacement, b) Combustion, c) Extended, and d) Decomposition. Among these, single replacement reactions involve one element replacing another in a compound, combustion reactions involve the burning of a substance in oxygen to produce heat and light, and decomposition reactions involve a single compound breaking down into two or more products. The term 'Extended' does not describe a known type of chemical reaction, making option C the correct answer.
Examples of other types of chemical reactions include combination (or synthesis) reactions, where two or more substances combine to form a new compound, and double replacement reactions, where the positive ions in two compounds switch places, forming two new compounds.