Select the option that is related to the fifth term in the same way as the second term is related to the first term and fourth term is related to third term.
SHIRT : RGISU :: KNIFE : JMIGF :: CHAIR : ?

Let's check the pattern for SHIRT → RGISU:
S $-1=$ R

H $+1=$ I → wait, the second letter is G, so H $-1=$ G

I → stays I, or maybe a different shift? Let's check:

S (19) $-1=$ R (18)

H (8) $-1=$ G (7)

I (9) $+0=$ I (9)

R (18) $+1=$ S (19)

T (20) $+1=$ U (21)

Let's check if this pattern (−1,−1,0,+1,+1) holds for KNIFE → JMIGF:

K (11) $-1=$ J (10)

N (14) $-1=$ M (13)

I (9) $+0=$ I (9)

F (6) $+1=$ G (7)

E (5) $+1=$ F (6)
The pattern is verified.

Now apply the same pattern to CHAIR:

C (3) $-1=$ B (2)

H (8) $-1=$ G (7)

A (1) $+0=$ A (1)

I (9) $+1=$ J (10)

R (18) $+1=$ S (19)

So, CHAIR becomes BGAJS.