n=1→an=a1 (first term)=16 (on the graph for n=1)→First term = 16
n=2→an=a2 (second term) = 4 (on the graph for n=2)→Second term = 4
ratio=(Second term)/(First term)=a2/a1=4/16
Simplifying the fraction dividing the numerator (4) by 4 and the denominator (16) by 4:
ratio=(4/4)/(16/4)→ratio=1/4
Answer: Option A. First term = 16, ratio = 1/4