Correct Answer - C
i. `r lt a. E = 0 `, since `Q = 0` ( fig.S2.54)
ii. `a lt r lt b. E = 0` , since `Q = 0` .
iii. `b lt r lt c`. Since `Q = + 2 q , E = (1)/( 4 pi epsilon_(0)) ( 2q)/(r^(2))`
iv. C lt r lt d. E = 0 , since `Q = 0`.
v. r gt d. E = (1)/( 4 pi epsilon_(0)) ( 6 q)/( r^(2))` , since `Q = + 6 q`.