Chlorination of toluene in presence of light and heat followed by treatment with aqueous NaOH gives :
(a) o-Cresol                     (b) p-Cresol                     (c) 2, 4-Dihydroxytoluene                   (d) Benzoic acid

On chlorination of toulene the possible products are
1. one  hydrogen replaced by Cl
2. two H replace by Cl
3. All H replaced by Cl
Note alkyl halide on treatment with Aq. NaOH gives alcohol (X replaced by OH) (nucliophillic substitution) 

consider case 1 we get C6H5CH2Cl  
consider case 2 we get 2 OH on same Carbon which is unstable so H20 gets eliminated which gives
                         Benzalhehyde 
consider case 3 we get 3 OH on same C atom again H20 eliminated and we get Benzoic acid 

check the options only only matching option is option d

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