If 50 ML of Solution Containing 2

If 50. mL of solution containing 2.0 × 10³ ppm sodium ion is diluted to 4.0 L, what is the final concentration of sodium ion?

A) 2.5 ppm
B) 2.5 × 10⁴ ppb
C) 2.5%
D) 2.5 mg/L
E) all of these are correct