Final answer:
The different electoral systems and their descriptions are: A) First-Past-the-Post, B) Proportional Representation, C) Single Transferable Vote, D) Mixed-Member Proportional. Each system has distinct characteristics and affects representation differently.
Step-by-step explanation:
In a First-Past-the-Post electoral system (A), voters directly vote for a candidate, and the one with the most votes wins, regardless of the percentage of the vote share. This system is straightforward but disadvantageous for smaller parties.
Proportional Representation (B) systems allocate seats to parties based on the percentage of the vote each party receives. This ensures fair representation for smaller parties.
Single Transferable Vote (C) systems allow voters to rank candidates, and those with sufficient first-preference votes are elected. The process continues until all seats are filled.
Mixed-Member Proportional (D) systems combine elements of both plurality and proportional representation systems, using both single-member districts and party lists.