removing ε production
I understood your confusion 

firstly here C,B,A,S all approach ε at one point

so solving in the method you solved previous example put ε one by one in S then consider all combinations like this

S-->ABCa/bD/BCa/ACa/ABa/Aa/Ba/Ca/a

A-->Bc/b/c

B-->b

C-->c

D-->d
firstly in S for (ABCa) put ε in A then B then C later BC,CA,AB,ABC 
so if you follow this fashion you get the answer