Which of the following scenarios reflect the isolation property?

a$.)$

$1.$ A transaction has completed executing.

$2.$ The changes are saved to volatile memory.

$3.$ The changes are then saved to non$-$volatile memory.

b$.)$

$1.$ The product quantity starts at $200.$

$2.$ Transaction $1$ runs to read the quantity of the product to be updated.

$3.$ Transaction $2$ attempts to read the quantity of the same product.

$4.$ Transaction $2$ has to wait until transaction $1$ is complete.

$5.$ Transaction $1$ updates the product quantity to reduce it by $100.$

$6.$ Transaction $2$ is now able to read the quantity to be updated.

$7.$ Transaction $2$ updates the product quantity to reduce it by $5.$

$8.$ The product quantity ends at $95.$

c$.)$

$1.$ The new letter column can only accept Y or N as options.

$2.$ The user attempts to enter in Maybe.

$3.$ The transaction is denied.

d$.)$

$1.$ A transaction has two SQL requests.

$2.$ Both successfully complete.

$3.$ The data is then committed.