Which of the following is not an ideal solution?

Which of the following is/are "not correct" for $CH_3OH + CH_3COOH$ mixture solution?
$(a)$ $\Delta H_{\text{mix}} < 0$
$(b)$ Does not obey Raoult's law
$(c)$ $\Delta H_{\text{mix}} > 0$
$(d)$ An example of ideal solution

Two liquids $A$ and $B$ have vapour pressure in the ratio $P_A^o : P_B^o = 1 : 3$ at a certain temperature. Assume $A$ and $B$ form an ideal solution and the ratio of mole fractions of $A$ to $B$ in the vapour phase is $4 : 3$. Then the mole fraction of $B$ in the solution at the same temperature is

The vapour pressures of chloroform $(CHCl_3)$ and dichloromethane $(CH_2Cl_2)$ at $298 \ K$ are $200 \ mmHg$ and $415 \ mmHg$,respectively. An ideal solution is prepared by mixing $59.75 \ g$ of $CHCl_3$ and $21.25 \ g$ of $CH_2Cl_2$. The mole fractions of chloroform and dichloromethane in the vapour phase,respectively,are:

Vapour pressure of pure acetone and chloroform at $328 \, K$ are $741.8 \, mm \, Hg$ and $632.8 \, mm \, Hg$ respectively. Assuming that they form an ideal solution over the entire range of composition,plot $p_{total}$,$p_{chloroform}$,and $p_{acetone}$ as a function of $x_{acetone}$. The experimental data observed for different compositions of the mixture is:

$100 \times x_{acetone}$	$0, 11.8, 23.4, 36.0, 50.8, 85.2, 64.5, 72.1$
$p_{acetone} / mm \, Hg$	$0, 54.9, 110.1, 202.4, 322.7, 405.9, 454.1, 521.1$
$p_{chloroform} / mm \, Hg$	$632.8, 548.1, 469.4, 359.7, 257.7, 193.6, 161.2, 120.7$

In a mixture of $A$ and $B$ components,the solution shows negative deviation when: