Nonpermissive Electoral Systems (Such as Single-Member District Plurality) Are Thought

Nonpermissive electoral systems (such as single-member district plurality) are thought to benefit a small number of large parties because:

A) they have a strong mechanical reductive effect on the way votes are translated into seats.
B) there are many incentives to engage in strategic voting.
C) there are many incentives to engage in strategic entry.
D) all of the above explain the benefits to larger parties.