An arithmetic sequence has this recursive formula

Option B is correct.    

Step-by-step explanation:

Given the recursive formula of arithmetic sequence

we have to find the explicit formula for the above sequence.

which is the common difference, d=-4

The explicit formula for A.P is

Option B is correct.

for any of you who need the translation here it is

step-by-step explanation:

find the angular size of the equatorial radius of the earth, if the horizontal parallax of the sun