两道GMAT语法题求解The electronics company has unveiled what it clai

两道GMAT语法题求解
The electronics company has unveiled what it claims to be the world’s smallest network digital camcorder,the length of which is that of a handheld computer,and it weighs less than 11 ounces.
A.to be the world’s smallest network digital camcorder,the length of which is that of a handheld computer,and it weighs
B.to be the smallest network digital camcorder in the world,which is as long as a handheld computer,weighing
C.is the smallest network digital camcorder in the world,which is as long as a handheld computer,and it weighs
D.is the world’s smallest network digital camcorder,which is as long as a handheld computer and weighs
E.is the world’s smallest network digital camcorder,the length of which is that of a handheld computer,weighing
我觉得D和合适啊,B “which” refers to the world,
Regardless of their form or function,all aerodynamically enhanced,curved objects made for throwing have been called boomerangs by non-Australians even since 1788,when Europeans saw Dharug-speaking men tossing “bumariny” in the area later known as Sydney.
A.Regardless of their form or function,all aerodynamically enhanced,curved objects made for throwing have been called boomerangs by non-Australians ever since 1788,
B.Regardless of their form or function,any aerodynamically enhanced,curved object made for throwing has been called a boomerang by non-Australians ever since 1788,
C.Ever since 1788,non-Australians have called all aerodynamically enhanced,curved objects made for throwing boomerangs,regardless of their form or function,from
D.Ever since 1788,any aerodynamically enhanced,curved object made for throwing has been called a boomerang by non-Australians,regardless of its form or function,from
E.Non-Australians have called all aerodynamically enhanced,curved objects made for throwing boomerangs ever since 1788,regardless of their form or function,from
我觉得A开头有个their,并没有指代对象啊.为什么要选A不选D?