Which of the following scenarios refilects the isolation property?

The product quantity starts at $200.$

Transaction $1$ runs to read the quantity of the product to be updated.

Transaction $2$ runs in parallel to read the quantity of the product to be updated.

Transaction $1$ updates the product quantity to reduce it by $100.$

Transaction $2$ updates the product quantity to reduce it by $5.$

The product quantity ends at $195.$

A fairly large update to the products table.

The update is saved to the logs$.$

The update starts to then save to the disk.

The system fails midway through.

When the system starts back up$,$ the committed transactions that haven't been written to disk are written.

Transaction $1$ reads a product's cost which is set at $$100.$

Transaction $1$ updates the product to set the price to $$90.$

Transaction $2$ reads the same product's cost and sees $$100.$

Transaction $1$ commits the cost.