Shipments of Product $x$ from a plant to a wholesaler are made in lots of $1500$ units each. The wholesaler's average demand for $x$ is $300$ units per week. The lead time from the plant to the wholesaler is $3$ weeks. The wholesaler pays for the shipments when they leave the plant.

What is the total of the wholesaler's current cycle plus pipeline inventories?

$850$ units

$750$ units

$1650$ units

$1800$ units