For an ideal solution, the correct option is:

• A

  ${∆}_{\mathrm{m}\mathrm{i}\mathrm{x}}\mathrm{ }\mathrm{S}=0$ at constant $\mathrm{T}$ and $\mathrm{P}$
• B

  ${∆}_{\mathrm{m}\mathrm{i}\mathrm{x}}\mathrm{ }\mathrm{V}\ne 0$ at constant $\mathrm{T}$ and $\mathrm{P}$
• Correct answer
  C

  ${∆}_{\mathrm{m}\mathrm{i}\mathrm{x}}\mathrm{ }\mathrm{H}=0$ at constant $\mathrm{T}$ and $\mathrm{P}$
• D

  ${∆}_{\mathrm{m}\mathrm{i}\mathrm{x}}\mathrm{ }\mathrm{G}=0$ at constant $\mathrm{T}$ and $\mathrm{P}$

Hence, the correct answer is option: 'C'.