请教各位前辈几道语法题！

dhhgh11

1.the technique of spectroscopy allows (analyst) of incoming light after it (has been) separated into (its) component wavelengths (by passage ) through a prism.

the answer is a,but why not d?how to translate it?

2.in the late 1800's,united states painter thomas eakins (develop ) a (broad),powerful realist (style that ) became (almost) expressionistic in his later years.

the answer is b,but I think c is also incorrect,

broad is a adj.,is there anything wrong?

thanks！

himba

my answer:

1: D---passing

2: A---developed