已知数列 {an}\left\{ {a}_{n}\right\}{an} 满足 a1=1,an−an+1=2anan+1{a}_{1} = 1,{a}_{n} - {a}_{n + 1} = 2{a}_{n}{a}_{n + 1}a1=1,an−an+1=2anan+1 , 则数列 {anan+1}\left\{ {{a}_{n}{a}_{n + 1}}\right\}{anan+1} 的前 8 项和为 ( )A. 817\frac{8}{17}178B. 1225\frac{12}{25}2512C. 78\frac{7}{8}87D. 89\frac{8}{9}98