A cheque$-$processing centre uses exponential smoothing to forecast the number of incoming cheques each month. The number of cheques received in June was $38$ million, while the forecast was $42$ million. A smoothing constant of $0\mathrm{.}15$ is used.

a$)$ Using exponential smoothing and given ${}_i$ the forecast for the month of July $=$ million cheques received. $($Round your response to one decimal place.$)$

b$)$ If the cheque$-$processing centre received $46$ million cheques in the month of July, then using exponential smoothing and given $,$ the forecast for the month of August $=$ million cheques received. $($Round your response to one decimal place.$)$

c$)$ Exponential smoothing may not be an appropriate method to use for the cheque$-$processing centre because

A$.$ the cheque$-$processing centre should observe a cyclical trend in its processing requirements.

B$.$ the cheque$-$processing centre should observe seasonality in its processing requirements

C$.$ the cheque$-$processing centre should observe an increasing trend in its processing requirements

D$.$ the cheque$-$processing centre's forecast is very hard to make as its processing requirements should have a very high variability.