select all the reactants

select all the reactants
Answer
Explanation:
Step1: Recall Reactants Definition
Reactants are substances before a reaction (left of arrow in equation). The top equation is ( \text{C} + \text{O}_2 \rightarrow \text{CO}_2 ). So reactants are C (carbon) and ( \text{O}_2 ) (oxygen molecule).
Step2: Identify Reactant Images
- Left image: two red O atoms ( ( \text{O}_2 ) ), matches reactant ( \text{O}_2 ).
- Middle image: single gray C atom, matches reactant C.
- Right image: ( \text{CO}_2 ) (product), not a reactant.