SAT Grammar Questions

SAT Grammar Questions
In neighborhoods throughout the US,one can encounter hundreds of different rope-jumping games,( which has its own rules )
应改成each with its own rules
那原句是因为its才错了吗,如果是jumping game的话,是不是原句就是对的呀?
A flurry of do-it-yourself books on the market today are inspiring homeowners to do their own repairs.
(A) are inspiring homeowners to do their own repairs
(D) is inspiring homeowners to do their own repairs
为什么应该选D?
还有一题
by including pieces of cloth,newspaper,wallpaper and other materials in his work,（the innovative Picasso was an important influence on twentieth-century art.） 为什么人前面也可以加THE?我觉得D选项Picasso was influential,with his innovation,over更好啊