A $0.10\mathrm{M}$ solution of $\mathrm{NaOH}$ ($40g/mol$) is required. Which procedure(s) give this concentration? (Volumes are additive.)

1. A$250\mathrm{mL}$ of $0.40\mathrm{M}$ $\mathrm{NaOH}$ is diluted with $750\mathrm{mL}$ of water.
2. B$100\mathrm{mL}$ of $0.30\mathrm{M}$ $\mathrm{NaOH}$ is mixed with $200\mathrm{mL}$ of $0.050\mathrm{M}$ $\mathrm{NaOH}$.
3. C$50\mathrm{mL}$ of $0.50\mathrm{M}$ $\mathrm{NaOH}$ is diluted with water to a final volume of $250\mathrm{mL}$.
4. D$2.0\mathrm{g}$ of $\mathrm{NaOH}$ is dissolved in water to make $400\mathrm{mL}$.