The highest number of helium atoms is in

\( 4 \text{ mol} \) of helium contains \( 4 \times N_A \) atoms, which is the largest quantity among all options (\( 4\text{ g} = 1\text{ mol} \), \( 2.271098\text{ L at STP} = 0.1\text{ mol} \), \( 4\text{ u} = 1\text{ atom} \)).