a$3(35$P$)$ NFT $($Non fungible Token$)$ are sold to the community within $1$ week they are released. After they are in community, people who bought them have $3$ options:

Option $1$: they can keep them and don't sell them

Option $2$: they can sell certain amount of them at the market

Option $3$: they use them to receive Level $1$ token. If an owner collects $4$ NFT he can have $1$ Level $1$ token. $($in other words, for $4$ NFT you can have $1$ Level $1$ token$)$

Develop the stock flow diagram for this model. Include model units and equations. $(35$P$)$