Answer: B and D

B. Data goes in the detail property: When you create a custom event, you pass the payload through the detail property, and the handler reads it with event.detail.
D. Propagation is limited by default: A custom event doesn’t bubble and isn’t composed unless you set bubbles: true and composed: true. By default it reaches only the immediate parent that listens for it.
javascript
// child component
const evt = new CustomEvent('select', { detail: { recordId: this.recordId } });
this.dispatchEvent(evt);

// parent component's handler
handleSelect(event) {
console.log(event.detail.recordId);
}

The other options are wrong:

A: @wire is a decorator that reads data from the platform into a component property. It isn’t how an event’s payload is passed.
C: An event travels up to the parent, never down to a child. Parents pass data to children through public @api properties or methods.

Correct answers are
B. Data may be passed In the payload of a custom event using a property called detail.
D. By default a custom event only propagates to it's immediate container.