For The CEO Payphone Hit in GTA Online's The Contract DLC, your target is a CEO filming a reality TV show at a construction site. All assassination bonus variants for this mission require you to use a scoped rifle to make the kill appear accidental.

Variant 1: Cargo Container

The first variant requires you to use a scoped rifle to take out the target with a cargo container.
When you reach the construction site, a white bag will be marked on your mini-map (similar to the one seen in Variant 3 of The Cofounder). The bag contains a scoped rifle.

Go to the white bag and interact with it to get your scoped rifle.

Aim down sights towards the construction site where the target is. You will find a hanging cargo container with a red arrow hovering over it.

You need to wait for the marked target to walk under the container.