Question

What is NOT the function of political parties? selecting the candidate conducting a census conducting the campaign campaign financing designing the platform

Answer 1

"conducting a census" is the only option from the list that is not a function of political parties, since these are best done by independent third parties. Although political parties can perform them if they choose. 

Answer 2

Political parties certainly choose their candidates, as well as carry out the campaign in a way that best suits a particular political option in terms of being adequate to the political views of the party. They also design a political campaign platform and deal with technical issues such as finance for the implementation and design of the campaign itself. Political parties can also conduct a census, they do it, and use them in campaigns, but usually for a better effect, they use a census conducted by some agencies concerned so that the results of the census "look" more objectively. It has a greater impact on the population than when it presents the results of its own conducted census.

The answer is. conducting a census.