Which of the following scenarios reflect the isolation property?

a$.)$

$1.$ There are $50$ desks available for purchase in the product table.

$2.$ In one transaction, the customer purchases $10$ desks.

$3.$ In the same transaction, the customer purchases $10$ desks.

$4.$ The validation check runs and sees there are $40$ desks left.

$5.$ The entire transaction is reverted.

b$.)$

$1.$ A user attempts to add an order into the database.

$2.$ They successfully add the customer, then add the order table.

$3.$ However, when trying to add the products to the order, the products no longer had any stock.

$4.$ The entire order has to be canceled.

c$.)$

$1.$ An HR employee updates Jeff's salary by increasing it by $2\mathrm{.}5\%.$

$2.$ The general manager updates Sally's salary by increasing it by $5\%.$

$3.$ The HR employee hasn't finished the transaction yet and gets on a call.

$4.$ The general manager updates Jeff's salary by increasing it by $5\%.$

$5.$ The HR employee's database session timed out.

$6.$ The database reverts Jeff's salary to what it was prior to the HR employee updating it and applies the $5\%$ increase by the general manager.

d$.)$

$1.$ Transaction $1$ updates customer $1\text{'}$s address.

$2.$ Transaction $1$ updates customer $2\text{'}$s address.

$3.$ Transaction $1$ commits the changes.

$4.$ The changes are queued in the disk cover waiting to be committed to the disk.

$5.$ The system fails and the changes are not written to memory.

$6.$ Once the database is started up again, the recovery management component saves the changes to memory.