The sales team requests a report detailing the number of units sold by date. Given the schema below, which array function correctly fills in the blank to generate the desired report?

Table orders: orderDate DATE, orderIds ARRAY Table orderDetail: orderId INT, unitsSold INT, salesAmt DOUBLE

SELECT orderDate, SUM(unitsSold)
FROM orderDetail od
JOIN (select orderDate, ___________(orderIds) as orderId FROM orders) o
ON o.orderId = od.orderId
GROUP BY orderDate