Answer:
B. The number of crickets in each container.
C. The kind of containers used.
Step-by-step explanation:
A control experiment can be defined as an experiment in which a condition assumed to be a probable cause of the effect is being compared to the same situation by the scientist without involving or using the suspected condition.
Controlled variable refers to anything or quantity such as group, person, event, etc., that is held constant by the researcher during an experiment and as such is limited.
In this scenario, the two constants in this experiment are;
I. The number of crickets in each of the three identical container.
II. The kind of containers used, they are all identical and as such would have the same properties.