What event changed the Republican Party's position on civil service reform?

the election of Rutherford B. Hayes as president

the assassination of President James Garfield

the establishment of the Civil Service Commission

the publishing of a popular collection of political cartoons

the assassination of President James Garfield

(B) the assassination of President James Garfield

Explanation:

The civil service reform was intended to ensure that positions in the federal government was given to people not on the basis of their political alliance with the ruling party, but based on the abilities of the individuals instead. The Republican Party, at first blocked this motion.

But after the assassination of President James Garfield by an individual who held delusions that the reason he wasn't chosen for a position in the federal government was because he did not have the 'right' political affliation, the party changed its position. This manifested in the Pendleton Civil Service Reform Act, signed into law by Garfield's successor, President Chester A. Arthur.