Suppose a processing step processes two products A and B$.$ The processing step can process $4$ units of A in an hour $($if it is only processing A$)$ and $6$ units of B in an hour $($if it is only processing B$).$

The process needs to maintain a $2$:$3$ ratio between the amounts of A and B produced $($i$.$e$.,$ for every two units of A$,$ the process needs to produce three units of B$).$

Based on this information, please answer the following questions.

Question $7$: If the process needss to maintain the $2$:$3$ ratio between A and B produced, which of the following repeating production cycles should be choosen?

Option $1)$ A$,$A$,$A$,$B$,$B$,...$

Option $2)$ A$,$A$,$B$,$B$,$B$,...$

Option $3)$ A$,$A$,$B$,$B$,....$

Option $4)$ A$,$B$,$B$,$B$,$B$,....$