What is the value of r of the geometric series? Sigma-Summation Underscript n = 1 Overscript 3 EndScripts 1.3 (0.8) Superscript n minus 1 A.) 0.8 B.) 1.3 C.) 3.0 D.) 3.2 (This is from Edg, sorry if the formatting gets messed up)