On monobromination of a hydrocarbon $\mathrm{A}\left({\mathrm{C}}_5{\mathrm{H}}_{12}\right)$the number of possible stereoisomers obtained can be ……(maximum)

CH₃CH₂CH₂CH₂CH₃ on mono bromination gives 4(out of which 2 are stereo isomers) isomers 

(CH₃)₂CHCH₂CH₃ on mono bromination gives 6 isomers (out of which 4 are stereo isomers)

(CH₃)₄C on mono bromination gives 1 isomer 

total 11 isomers are possible