Mind blowing reagent

An optically active organic compound (A) (having 8 C, 13 H and 1 Cl only) does decolourise bromine water solution. (A) on treatment with KOH can produce 2 products in principle but infact only one product (B) (having 8 C and 12 H only) is obtained. (B) on treatment with ozone followed by work up with hydrogen peroxide yields (C) (with 8 C , 12 H and 4 O only) which cannot be resolved into enantiomers. (C) on heating with NaOH/CaO yields (D) (having 6 C and 12 C only) which on monochlorination yields E (having 6 C , 11 H and 1 Cl only) as single isomer. Find the no. of C-atoms in D.