The type of party system in practice is defined by the
relationship between the parties and electorate
structure of the political parties
manner in which the parties operate
number of political parties in a country
Correct answer is D
The type of party system in practice is defined by the number of political parties in a country.
The party system which a country operates depends on the constitution and what such country has in mind. It could be one party, two-party or multi-party system of government.