Which pair of variables has a clear causal link between the two named variables?
the number of hats sold and the number of mittens sold in a city
the amount of butter and the amount of bread consumed by a family
the number of notebooks sold and the number of pens sold in a stationery store
the number of air conditioners sold per day in a city and the daily temperature
the number of hours a person can swim and the depth of the pool
nextreset

The number of air conditioners sold per day in a city and the daily temperature

Step-by-step explanation:

We know that if there is a causal relationship between two variables then one variable is responsible for causing the other variable.

there is no causal relationship between the variables since both are independent variables.

there is no causal relationship between the variables since both are independent variables.

there is no causal relationship between the variables since both are independent variables.

there can be causal relationship between the variables since by increasing  or decreasing temperature the the number of air conditioners sold per day in a city can be increased or decreased respectively.

there is no causal relationship between the variables since both are independent variables.

D.  

the number of air conditioners sold per day in a city and the daily temperature