Which statement best describes how a catalyst can speed up a chemical reaction? The catalyst decreases the activation energy needed.
The catalyst increases the concentration of products.
The catalyst binds to enzymes to release substrates.
The catalyst increases the concentration of reactants.

thinking it would be d not too sure but i think it's right

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

wegner's theory did not explain how the continents could move

explanation: