The carbon - carbon bond length in graphite is :

Answer

A,B

Explanation

(A)`(X'_A)/(X_B)=(P_A^@X_A)/(P_B^@X_B)`
`(X'_A)/(X'_B)gt X_A/X_B ( "If" P_A^@ gt P_B^@)`
(B)If `P_A^@` is more, more A will evaporate more and B will stay back in the solution.
(C )`P_T=P_A^@X_A+P_B^@X_BneP_A^@+P_B^@`
(D)`If P_A^@ gt P_B^@` . Then `P_A^@ gt P_T gt P_B^@`
`P_A^@ gt P_A^@X_A + P_B^@X_B gt P_B^@`.Hence boiling point of solution is more than A but less than B.