$\begin{array}{1 1}(a)\;P-NO_2C_6H_4COOH\text{ is less acidic than the meta isomer}\\(b)\;P-NO_2C_6H_4COOH\text{ is more acidic than the meta isomer}\\(c)\;\text{P-chloro benzoic acid is more acidic than its meta isomer}\\(d)\;\text{all above}\end{array}$
