Identify the sentences with correct parallel structure. Check all that apply.

As receptionist, his duties include answering the phone, forwarding calls, and taking messages.

Hanging out by the copy machine, congregating by the water cooler, and visiting in the hallways are forbidden at headquarters.

The new project management software was implemented smoothly, but employee training requires additional resources due to its complexity.

While the marketing campaign generated high website traffic, conversion rates remained low, prompting a reevaluation of the sales funnel.