Question from the Angular 4 (legacy) test

Given the following code

const routes: Routes = [{
    path: 'parent',
    component: AbstractParentComponent,
    children: [
        {
            path: '',
            component: ParentComponent
        },
        {
            path: 'child',
            component: ChildComponent
        }
    ]
}];

With the following components:

// abstractparent.component.ts
import {Component} from '@angular/core';

@Component({
    selector: 'app-abstract-parent',
    template: 'Parent: <router-outlet></router-outlet>'
})
export class AbstractParentComponent {
    constructor() {
    }
}

// parent.component.ts
import {Component} from '@angular/core';

@Component({
    selector: 'app-parent',
    template: 'Parent'
})
export class ParentComponent {
    constructor() {
    }
}

// child.component.ts
import {Component} from '@angular/core';

@Component({
    selector: 'app-child',
    template: '<p>child</p>'
})
export class ChildComponent {
    constructor() {
    }
}

What will the page at the URL /parent/child display?