Please help me answer the question

fourth option

Step-by-step explanation:

Common difference is given by difference of two consecutive term

d = nth term - (n-1)th term

for all the  series lets take second term as nth term

and first term as (n-1)th term

for first series

n th term = -3 1/2 = -3.5

(n-1)th term = -5

therefore

d= -3.5 -(-5) = -3.5 +5 = 1.5

for second series

n th term = 4 1/2 = 4.5

(n-1)th term = 2 1/2 = 2.5

therefore

d= 4.5 -(2.5) =2

for third series

n th term = 3

(n-1)th term =1.5

therefore

d= 3 - 1.5 = 1.5

for fourth series

n th term = -1.5

(n-1)th term = -4

therefore

d= -1.5 -(-4) = -1.5 + 4 = 2.5 = 2 1/2

Thus, based on above solution option four has common difference of 2 1/2

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right