Which type of queuing model would be best for analyzing an automated car wash?

Constant service (M/D/1) model

Explanation:

In queueing theory, an M/D/1 queue stands for the length of the queue in a system having a single server, where the arrivals are usually determined by a Poisson process.

In this theory the time for job service are constant.This model name is written in Kendall's notation is the standard system used to describe and classify a queueing node.Kendall described queueing models in 1953 using three factors written A/S/c where A denotes the time between arrivals to the queue, S the service time distribution and c the number of service channels open at the node.

i would say b. research typically uses a variety of sources