Big Cure and Little Cure are both pharmaceutical companies. Big Cure presently has a potential "blockbuster" drug before the Food and Drug Administration $($FDA$)$ waiting for approval. If approved, Big Cure's blockbuster drug will produce $$1$ billion in net income for Big Cure. Little Cure has $10$ separate less important drugs before the FDA waiting for approval. If approved, each of Little Cure's drugs would produce $$100$ million in net income for Little Cure. The probability of the FDA approving a drug is $50\%.$

The standard deviation of Little Cure's average net income for their ten new drugs is closest to:

$$16$ million.

$$25$ million.

$$500$ million.

$$50$ million.