DO I W - n+. Which equation should be used to calculate the 43rd partial sum for the arithmetic sequence { a,} = 43 5 76 O A. S43 + 2 4 4 43 133 O B. S43 + 2 8 O C. S43 =1+(43-1). O D. S43 1+ (43-1) CO | W\f5 DO | un Calculate Sis for the arithmetic sequence defined by { a,} 16 O A . 65 2 O B. 65 O C. 65 8 O D. 65 2Calculate the sum of the rst 8 terms of the arithmetic sequence in which as = -1 and the common difference is d - 3. O A. 216 O B. -54 O C. 2|]l O D. 115