At room temperature, NaCl(s) and KCl(s) were taken in equal masses and dissolved in equal volumes of water in two separate closed containers I and II respectively. Of the following, correct option/s is/are

A

To compare molarities in (I) and (II), masses of both the solutions need to be known

B

Molalities cannot be compared without measuring the mass of water added in each case

C

If (I) and (II) are completely transferred into another container (III), $$[\text{Cl}^-]$$ in (III) will be sum of that in (I) and (II)

D

Information given is sufficient to compare the vapour pressures in (I) and (II)