In the context of electric vehicle batteries, consider the following elements: I. Cobalt II. Graphite III. Lithium IV. Nickel. How many of the above usually make up battery cathodes?

• I. Cobalt: Used in many Li-ion battery cathodes such as LCO, NMC and NCA. Verdict: Correct.
• II. Graphite: Graphite is usually used in the anode, not the cathode, in conventional EV lithium-ion batteries. Verdict: Incorrect.
• III. Lithium: Lithium is a core constituent of common EV battery cathode chemistries like lithium cobalt oxide, lithium iron phosphate, and NMC. Verdict: Correct.
• IV. Nickel: Nickel is used in several cathode chemistries, especially NMC and NCA batteries. Verdict: Correct.

Thus, three of the above usually make up battery cathodes. Answer: (c) Only three.