When is a session or contact bucketed under “Paid search” in HubSpot?

When a visitor comes from your paid search advertising campaigns‌ — ‌like from your Google Ads
When a visitor comes from advertising campaigns made on social media websites or apps (like TikTok, LinkedIn, or Instagram)
When a visitor comes from any agency partner you’ve hired or consulted with historically
When a visitor has a paid subscription to a blog (like Medium) or news site and is then directed to your website from an article link

The correct answer is:

When a visitor comes from your paid search advertising campaigns‌ — ‌like from your Google Ads