Swim4Life Provides Swimming Classes and Training in South East Queensland

Swim4Life provides swimming classes and training in South East Queensland. Swim4Life offers four training levels: Learn to Swim Baby, Learn to Swim Junior, Learn to Swim Senior, Swim Squad. In November 2019, the firm's information system produced the following data $$\begin{array} { | l | l | l | l | l | l | } \hline & \begin{array} { l } \text { No of Swirn } \\\text { Teachers }\end{array} & \text { No of Students } & \text { Area Occupied } & \begin{array} { l } \text { Number of } \\\text { Classes }\end{array} & \text { Direct Costs } \\\hline \text { Baby } & 4 & 20 & 10 \% & 108 & \$ 1,000 \\\hline \text { Jurior } & 3 & 24 & 40 \% & 94 & \$ 1,500 \\\hline \text { Serior } & 5 & 15 & 20 \% & 84 & \$ 3,000 \\\hline \text { Squad } & 3 & 9 & 30 \% & 48 & \$ 1,000 \\\hline\end{array}$$ Regardless of level, students pay $15 per hour for lessons. Only 5 swimmers can be supervised by the teacher in each lesson. Swim4Life also provides lessons to school students who come with their school during school hours. These lessons are provided at a discounted rate of $12 per child.
Costs associated with the Swim4Life operations for November 2019 included:
Facility rent $2,500
Provision of Life Savers $800
Utilities $1,100
Computer equipment depreciation $800
Advertising $400
Training $1,500
The number of students in each level is most likely to be a cost driver for:

A) Wages for swim teachers
B) Advertising costs
C) Utility costs
D) Price charged for swim lessons